Improve SEO by having the 5.x docs take priority

[PaulRBerg]

Problem

User searches for "OpenZeppelin AccessControl" on Google, and they open this URL:

https://docs.openzeppelin.com/contracts/2.x/access-control

Which contains the documentation for the 2.x contracts, which are not the most up-to-date. As of posting this issue, the latest version is 5.x.

There's no warning or anything in the docs.

Toggle to see screenshot

Solution

• Add a warning at the top of every 2.x/3.x/4.x docs page that the latest version is 5.x and users should switch to that.
• Make the warning float, so it is still visible if the user scrolls down.
• Provide a sitemap with different <sitemod> timestamps, e.g. below.
• (OPTIONAL) Stop indexing the old docs.

Example Sitemap

The sitemap tells Google: "Hey, this is the up-to-date version—crawl and rank this". This alone won't de-index the old pages, but it increases the chances that the new ones take precedence.

<url>
  <loc>https://docs.openzeppelin.com/contracts/5.x</loc>
  <lastmod>2025-03-01</lastmod>
</url>
<url>
  <loc>https://docs.openzeppelin.com/contracts/4.x</loc>
  <lastmod>2024-06-01</lastmod>
</url>

[PaulRBerg]

cc @ernestognw @ericglau

[frangio]

Provide a sitemap with different <lastmod> timestamps

This will be more more difficult. Antora issue about it: https://gitlab.com/antora/antora/-/issues/661