fixes broken links in docs (#11058)

There were some broken links which are fixed with this PR. Is there a way to check for internal and/or external broken links at build time with Gatsby?

There are some remaining broken links, mainly due to outdated packages. Those can be found with an online broken links checker:

- The dependency `gatsby-plugin-google-fonts` linked in https://www.gatsbyjs.org/starters/ericwindmill/gatsby-starter-docs/ does not exist anymore in this repo. Link to its [npm package](https://www.npmjs.com/package/gatsby-plugin-google-fonts)?
- Several links from packages I cannot find in the current master branch:
  - https://www.gatsbyjs.org/packages/gatsby-plugin-purgecss/LICENSE
  - https://www.gatsbyjs.org/packages/gatsby-source-ghost/LICENSE
  - https://www.gatsbyjs.org/packages/gatsby-plugin-matomo/CHANGELOG.md
  - https://www.gatsbyjs.org/packages/gatsby-source-stripe/CODE_OF_CONDUCT.md
  - https://www.gatsbyjs.org/packages/gatsby-source-stripe/CONTRIBUTING.md
- https://www.gatsbyjs.org/packages/gatsby-source-craftcms/ links to https://github.com/gusnips/gatsby-craftcms-example but should link to https://github.com/gusnips/gatsby-source-craftcms (refresh repo?)

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## Description

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## Related Issues

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  Link to the issue that is fixed by this PR (if there is one)
  e.g. Fixes #1234, Addresses #1234, Related to #1234, etc.
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docs/blog/2018-10-16-why-mobile-performance-is-crucial/index.md

@@ -132,7 +132,7 @@ Caching a traditional CMS website is another possibility -- though this often cr
 
 But if delivery optimization is _hard_, payload optimization can be _near impossible_ to deliver within time and budget for many agencies and enterprises.
 
-Comprehensive checklists [weigh in at around 40 items](https://www.smashingmagazine.com/2018/01/frontend-performance-checklist-2018-pdf-pages/), including points like route-based code splitting, HTTP/2 asset serving, background prefetching, lazy-loading non-critical assets, service workers, dead code elimination, and server-side rendering. Each of these points is technically feasible but quite rare.
+Comprehensive checklists [weigh in at around 40 items](https://www.smashingmagazine.com/2019/01/front-end-performance-checklist-2019-pdf-pages/), including points like route-based code splitting, HTTP/2 asset serving, background prefetching, lazy-loading non-critical assets, service workers, dead code elimination, and server-side rendering. Each of these points is technically feasible but quite rare.
 
 Among the many implementation challenges are:
 

docs/blog/2018-10-18-creating-compelling-content-experiences/index.md

@@ -53,7 +53,7 @@ Often, to ensure a fast site, you'll need both.
 
 To do delivery optimization, you'll need to pick a JAMStack site generator like Hugo or Gatsby.
 
-To do payload optimization, your team will need to implement a [long performance checklist](https://www.smashingmagazine.com/2018/01/frontend-performance-checklist-2018-pdf-pages/), or pick a framework such as Gatsby that [performs payload optimization](https://www.gatsbyjs.org/features/#legend) out of the box.
+To do payload optimization, your team will need to implement a [long performance checklist](https://www.smashingmagazine.com/2019/01/front-end-performance-checklist-2019-pdf-pages/), or pick a framework such as Gatsby that [performs payload optimization](https://www.gatsbyjs.org/features/#legend) out of the box.
 
 ### Fourth, choose your content mesh
 

docs/blog/2018-12-31-how-we-do-high-impact-ux-research/index.md

@@ -143,4 +143,4 @@ Sign up for a 15, 30, or 60 minute interview to tell me your experiences with Ga
 
 ## Know someone who has never used Gatsby before?
 
-If you know someone who might like to get an Amazon gift card for participating in a usability test for first-time visitors to Gatsby, [submit your contact info and your friend’s contact info here!](https://docs.google.com/forms/d/e/1FAIpQLSeP4Z-7OnBeR2gyaLOu-N9GHQ59EFhIPqvzdp0UU70Fj4Bw2w/viewfor)
+If you know someone who might like to get an Amazon gift card for participating in a usability test for first-time visitors to Gatsby, [submit your contact info and your friend’s contact info here!](https://docs.google.com/forms/d/e/1FAIpQLSeP4Z-7OnBeR2gyaLOu-N9GHQ59EFhIPqvzdp0UU70Fj4Bw2w/viewform)

docs/blog/2018-2-27-why-i-upgraded-my-website-to-gatsbyjs-from-jekyll/index.md

@@ -36,7 +36,7 @@ As I had some free time on my hands, why not rewrite everything again and keep m
 
 ## Final Form — Gatsby
 
-[Gatsby](https://www.gatsbyjs.org/) is a static site generator that can render sites from markup documents using templates defined as React components. It functions similarly to Jekyll, where you can pick a [starter project](https://github.com/gatsbyjs/gatsby-starter-blog), [drop in](https://github.com/gatsbyjs/gatsby-starter-blog/blob/master/src/pages/hello-world/index.md) some markdown documents for articles, and [be rewarded](https://gatsbyjs.github.io/gatsby-starter-blog/) with a website with minimal effort.
+[Gatsby](https://www.gatsbyjs.org/) is a static site generator that can render sites from markup documents using templates defined as React components. It functions similarly to Jekyll, where you can pick a [starter project](https://github.com/gatsbyjs/gatsby-starter-blog), [drop in](https://github.com/gatsbyjs/gatsby-starter-blog/blob/master/content/blog/hello-world/index.md) some markdown documents for articles, and [be rewarded](https://gatsbyjs.github.io/gatsby-starter-blog/) with a website with minimal effort.
 
 It offers much much more, however. Gatsby lets me leverage all the modern tools for building web applications and to add interactive experiences for visitors like a fully fledged [React](https://reactjs.org/) application. Not only that, it is unlike traditional single page applications, and works _without_ JavaScript! Things would certainly be more complicated if I were to add a JavaScript compilation pipeline to a Jekyll site, and a JavaScript framework would be a better fit.
 

docs/docs/api-proxy.md

@@ -4,7 +4,7 @@ title: "Proxying API Requests in Development"
 
 ## Resources
 
-If you’re not familiar with Gatsby’s lifecycle, see the overview [Gatsby Lifecycle APIs](/gatsby-lifecycle-apis/).
+If you’re not familiar with Gatsby’s lifecycle, see the overview [Gatsby Lifecycle APIs](/docs/gatsby-lifecycle-apis/).
 
 ## Proxying API requests in development
 

docs/docs/api-specification.md

@@ -11,7 +11,7 @@ on the back burner btw until after v1 comes out).
 
 ## Prerequisites
 
-If you’re not familiar with Gatsby’s lifecycle, see the overview [Gatsby Lifecycle APIs](/gatsby-lifecycle-apis/).
+If you’re not familiar with Gatsby’s lifecycle, see the overview [Gatsby Lifecycle APIs](/docs/gatsby-lifecycle-apis/).
 
 ## Plugins
 

docs/docs/debugging-replace-renderer-api.md

@@ -4,7 +4,7 @@ title: Debugging replaceRenderer API
 
 ## Prerequisites
 
-If you’re not familiar with Gatsby’s lifecycle, see the overview [Gatsby Lifecycle APIs](/gatsby-lifecycle-apis/).
+If you’re not familiar with Gatsby’s lifecycle, see the overview [Gatsby Lifecycle APIs](/docs/gatsby-lifecycle-apis/).
 
 ## What is the `replaceRenderer` API?
 

docs/docs/how-to-label-an-issue.md

@@ -24,7 +24,7 @@ Anyone who's a member of the [Gatsby Maintainers team](https://github.com/orgs/g
 
 You can get an invite to the team by having a Pull Request merged into the Gatsby project. Check out the list of [`help wanted`](https://github.com/gatsbyjs/gatsby/labels/%F0%9F%93%8D%20status%3A%20help%20wanted) issues and the [How To Contribute Guide](/docs/how-to-contribute/) to get started.
 
-**NOTE:** If you’ve already had a pull request merged and you have _not_ been invited to the maintainers team, please go to [the dashboard](https://store.gatsbyjs.org/account/dashboard) and request a discount code. You should get an invite to the team — _and you get free Gatsby swag!_ If that doesn’t work, please email team@gatsbyjs.com and we'll get you invited.
+**NOTE:** If you’ve already had a pull request merged and you have _not_ been invited to the maintainers team, please go to [the dashboard](https://store.gatsbyjs.org/) and request a discount code. You should get an invite to the team — _and you get free Gatsby swag!_ If that doesn’t work, please email team@gatsbyjs.com and we'll get you invited.
 
 ## How to label an issue
 

docs/docs/static-vs-normal-queries.md

@@ -33,8 +33,8 @@ TODO: in query-watcher.js/handleQuery, we remove jsonName from dataDependencies.
 
 ### Usages
 
-- [websocket-manager](TODO). TODO
-- [query-watcher](TODO).
+- [websocket-manager](#TODO). TODO
+- [query-watcher](#TODO).
 
   - `getQueriesSnapshot` returns map with snapshot of `state.staticQueryComponents`
   - handleComponentsWithRemovedQueries. For each staticQueryComponent, if passed in queries doesn't include `staticQueryComponent.componentPath`. TODO: Where is StaticQueryComponent created? TODO: Where is queries passed into `handleComponentsWithRemovedQueries`?

docs/features/gatsby-specs.csv

@@ -21,7 +21,7 @@ Performance,Faster content delivery,Static content,3,3,1,2,"Can you build your s
 Gatsby supports this out of the box; adoption is possible with <a href=""https://fossbytes.com/get-jekyll-blog-work-offline/"" target=""_blank"">Jekyll</a> and <a href=""https://wordpress.org/plugins/offline-content/"">WordPress</a>. Squarespace <a href=""https://answers.squarespace.com/questions/56762/i-need-to-run-a-demo-of-my-squarespace-website-offline.html"">doesn't currently support</a> any offline access."
 ,,Prefetch linked pages,3,1,1,0,"<p>Gatsby supports content pre-fetching, out of the box. This means that when a page loads, the content needed to load the next link you click will be loaded in the background while you browse the page.</p>
 
-<p>You can put this together in <a href=""https://stackoverflow.com/questions/9951179/this-is-my-jekyll-with-hash-routing-setup-strategy-is-there-a-better-way"" target=""_blank>Jekyll</a>. The situation is <a href=""https://trevan.co/observations-on-frontend-routing-wordpress/"">considerably more tricky</a> for WordPress & requires maintaining dual PHP and JS templates.</p> "
+<p>You can put this together in <a href=""https://stackoverflow.com/questions/9951179/this-is-my-jekyll-with-hash-routing-setup-strategy-is-there-a-better-way"" target=""_blank>Jekyll</a>. The situation is <a href=""https://trevan.co/observations-on-front-end-routing-wordpress/"">considerably more tricky</a> for WordPress & requires maintaining dual PHP and JS templates.</p> "
 ,,Page caching,3,3,2,0,"<p>Fingerprinting static resources that aren't expected to change lets browsers serve content locally when a user visits a page they've already been to, as opposed to making an extra network call.</p>
 <p>Gatsby and Jekyll support this out of the box, while WordPress allows this via plugins and Squarespace <a href=""https://answers.squarespace.com/questions/173452/enabling-browser-cache-for-sqaurespace-site.html"">doesn't allow it</a> at all.</p>"
 ,,No extraneous code fetching,3,3,3,3,Extraneous code fetches are typically done by single-page applications written in various JS frameworks; on page load they fetch the code needed to run the entire application rather than just the page that's loaded. Website-building frameworks tend to be fiine on this.

scripts/gatsby-plugin-checker/plugins.json

@@ -15,7 +15,7 @@
 	{"name":"@ptb/gatsby-1-config-css-modules","blacklist":false,"notified":false},
 	{"name":"@ptb/gatsby-plugin-pug","blacklist":false,"notified":false},
 	{"name":"@ptb/gatsby-plugin-react-helmet","blacklist":false,"notified":false},
-	{"name":"@sb-konzept/gatsby-source-storyblok","blacklist":false,"notified":false},
+	{"name":"@storyblok/gatsby-source-storyblok","blacklist":false,"notified":false},
 	{"name":"@scion-scxml/sciblog","blacklist":false,"notified":false},
 	{"name":"@spraoi/gatsby-plugin","blacklist":false,"notified":false},
 	{"name":"@theplayerstribune/gatsby-source-wordpress-plus","blacklist":false,"notified":false},