* master: (26 commits)
  Publish
  [feat] Extract internal plugin for automatically creating pages so we can reuse for other directories (#4490)
  fix(contentful): properly delete deleted entries and assets (#5756)
  Fix typo
  add Linda's post (#5817)
  [gatsby-source-contentful] Fix prepareJSONNode for array normalization (#5107)
  Process Contentful images inlined in markdown (#5542)
  feat(contentful): add traced SVGs to Contentful images (#5659)
  [SQIP] Add documentation (#5287)
  Add site to showcase (#5819)
  [gatsby-remark-copy-linked-files] Support reference-style images (#5818)
  Update docs for gatsby-plugin-catch-links (#5843)
  Added ⋅ representing a space to sub-list examples to reflect actual code (#5829)
  Adding tigerfacilityservices.com to showcase (#5855)
  fix schema type conflict reporter regressions (#5805)
  [gatsby-plugin-feed] Support nested output directory (#5820)
  Make cache available to the plugins (#5840)
  [gatsby-source-contentful] update data and jest snapshots (#5802)
  [gatsby-plugin-manifest] Replace all manifest.json with manifest.webmanifest in comments/docs (#5157)
  Update deploy-gatsby.md (#5800)
  ...

# Conflicts:
#	docs/tutorial/part-one/index.md
#	examples/using-sqip/src/components/polaroid.js
#	packages/gatsby-image/README.md
#	packages/gatsby-image/package.json
#	packages/gatsby-plugin-catch-links/package.json
#	packages/gatsby-plugin-feed/package.json
#	packages/gatsby-plugin-manifest/package.json
#	packages/gatsby-plugin-page-creator/src/gatsby-node.js
#	packages/gatsby-remark-copy-linked-files/package.json
#	packages/gatsby-source-contentful/package.json
#	packages/gatsby-source-contentful/src/__tests__/__snapshots__/normalize.js.snap
#	packages/gatsby-source-contentful/src/extend-node-type.js
#	packages/gatsby-source-contentful/src/gatsby-node.js
#	packages/gatsby-source-contentful/src/normalize.js
#	packages/gatsby-transformer-remark/package.json
#	packages/gatsby-transformer-remark/src/__tests__/__snapshots__/gatsby-node.js.snap
#	packages/gatsby-transformer-sqip/package.json
#	packages/gatsby-transformer-sqip/src/extend-node-type.js
#	packages/gatsby/package.json
#	packages/gatsby/src/bootstrap/load-plugins/__tests__/__snapshots__/load-plugins.js.snap
#	packages/gatsby/src/bootstrap/load-plugins/load.js
#	www/src/data/sites.yml