v0.34.x: Removing all the vuepress related build files and references (backport #253)

[mergify]

This is an automatic backport of pull request #253 done by Mergify.
Cherry-pick of d159562 has failed:

On branch mergify/bp/v0.34.x/pr-253
Your branch is up to date with 'origin/v0.34.x'.

You are currently cherry-picking commit d159562d0.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	deleted:    docs/.textlintrc.json
	deleted:    docs/.vuepress/styles/index.styl
	deleted:    docs/package-lock.json
	deleted:    docs/post.sh
	deleted:    docs/pre.sh
	deleted:    docs/stop-words.txt

Unmerged paths:
  (use "git add/rm <file>..." as appropriate to mark resolution)
	both modified:   Makefile
	deleted by us:   RELEASES.md
	deleted by them: docs/.vuepress/config.js
	deleted by them: docs/.vuepress/redirects
	both modified:   docs/DOCS_README.md
	deleted by us:   docs/architecture/README.md
	deleted by them: docs/package.json
	deleted by them: docs/versions

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/github/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

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