fix(v2): remove duplicate section on Versions page

[lex111]

Motivation

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]

✔️ Deploy preview for docusaurus-2 ready!

🔨 Explore the source changes: e69efc8

🔍 Inspect the deploy logs: https://app.netlify.com/sites/docusaurus-2/deploys/5fe9e8ea8b3ed80008ab6788

😎 Browse the preview: https://deploy-preview-3960--docusaurus-2.netlify.app

[github-actions]

⚡️ Lighthouse report for the changes in this PR:

Category	Score
🟠 Performance	72
🟢 Accessibility	99
🟢 Best practices	100
🟢 SEO	100
🟢 PWA	95

Lighthouse ran on https://deploy-preview-3960--docusaurus-2.netlify.app/classic/

[github-actions]

Size Change: +8 B (0%)

Total Size: 155 kB

ℹ️ View Unchanged

Filename	Size	Change
website/build/blog/2017/12/14/introducing-docusaurus/index.html	20.7 kB	0 B
website/build/docs/introduction/index.html	180 B	0 B
website/build/index.html	5.82 kB	0 B
website/build/main.********.js	111 kB	+8 B (0%)
website/build/styles.********.css	17.6 kB	0 B

_{compressed-size-action}

[slorber]

thanks :)