chore: remove beta.5 docs

[lex111]

Motivation

Currently because of 15 min timeout the production site can not build successfully, so we should remove the oldest beta version of docs.

Since I don't have access to Netflify, I can't archive v5 docs in with the site name "docusaurus-2", so using the previous deploy for now.

Have you read the Contributing Guidelines on pull requests?

Yes

Test Plan

Preview

Related PRs

(If this PR adds or changes functionality, please take some time to update the docs at https://github.com/facebook/docusaurus, and link to your PR here.)

[netlify]

✔️ [V2]

🔨 Explore the source changes: a42f214

🔍 Inspect the deploy log: https://app.netlify.com/sites/docusaurus-2/deploys/616a6c3570b52a00080ba6e7

😎 Browse the preview: https://deploy-preview-5719--docusaurus-2.netlify.app

[github-actions]

⚡️ Lighthouse report for the changes in this PR:

Category	Score
🟠 Performance	75
🟢 Accessibility	98
🟢 Best practices	100
🟢 SEO	100
🟢 PWA	95

Lighthouse ran on https://deploy-preview-5719--docusaurus-2.netlify.app/

[github-actions]

Size Change: -42.5 kB (-5%) ✅

Total Size: 843 kB

Filename	Size	Change
website/.docusaurus/globalData.json	38.1 kB	-12.4 kB (-25%)	🎉
website/build/assets/js/main.********.js	424 kB	-32.6 kB (-7%)	✅
website/build/blog/2017/12/14/introducing-docusaurus/index.html	67.7 kB	+350 B (+1%)
website/build/blog/index.html	38.5 kB	+350 B (+1%)
website/build/docs/index.html	45.7 kB	+350 B (+1%)
website/build/docs/installation/index.html	53.4 kB	+338 B (+1%)
website/build/index.html	31.2 kB	+350 B (+1%)
website/build/tests/docs/index.html	26.6 kB	+350 B (+1%)
website/build/tests/docs/standalone/index.html	23.3 kB	+350 B (+2%)

ℹ️ View Unchanged

Filename	Size
website/build/assets/css/styles.********.css	93.8 kB

_{compressed-size-action}

[lex111]

It's not helps, build still failed https://app.netlify.com/sites/docusaurus-2/deploys/616a6e6564d6c90008aeb35f

[slorber]

FYI the docusaurus-2 Netlify project builds are public: https://app.netlify.com/sites/docusaurus-2/deploys

There's no concept of "archiving" on Netlify: I just take a recent immutable deploy URL with the version to archive in the URL.

About the failure, there seems to be an issue due to translated content, trying to figure this out

[slorber]

Looks like a Crowdin weird issue