Improve copy-to-clipboard, fix home link, clean up exampleSite

[helfper]

Some fixes and clean-ups:

• copy-to-clipboard icon looked stretched
• Home link didn't work correctly when base URL has some path
• Typo in custom theme's variable: --MENU-HOME-LINK-HOVERED-color
• Fixed some exampleSite typos and other minor clean-ups

[McShelby]

Thanks for the patch, I'll take a look into it.

Some hint for the next time: please submit separtate PRs for each individual issue. This makes cherry picking easier in case a maintainer don't want to merge everything.

[McShelby]

I've tried to review your patch but it is really hard with all the little things that got fixed.

I'ld really appreciate it, if you could split up each individual feature fix into a separate patch. It doesn't need to be a PR.

[McShelby]

I've fixed all the documentation stuff, whitespace issues and code block / code fence formatting in the 2.0.0 branch.

@helfper: What's left to do is integrating the bug fixes of your patch.

[helfper]

@McShelby I've split the PR into multiple commits. Let me know if you prefer separate PRs instead.

[McShelby]

I've checked all patches and so far everything looks fine.
@helfper: Just a final question: What was the reason to require a newer hugo version for netlify?

[McShelby]

I may answer myself: Because with the current setup at https://relearn.netlify.app/tags/ the page doesn't show any content.

[helfper]

Yes, taxonomy kinds were renamed in Hugo 0.73.0: https://github.com/gohugoio/hugo/releases/tag/v0.73.0
The theme had already been updated to reflect that (somewhat incorrectly in header.html though): a7a2954
But the Hugo version was not changed in Netlify, so things got out of sync.