Add "Latest" To Docsite Learn Versioning

[mcmah309]

Derived from: #436

The latest tag should be used in addition to version number. Currently the learn link uses the latest version number https://dioxuslabs.com/learn/0.6 . Using latest would allow users to create bookmarks to the current docs. For search engines, like google, they don't really understand that versions like 0.5 are obsolete until more users start using the 0.6 docs and enough time has past. Therefore a lot of google searches for questions lead to old documentation like 0.5 or 0.4. If something like latest was also used, overtime as these pages are used more frequently, they will be served more.

Though, as outlined in the linked issue

We have also added noindex to the old documentation to remove it from search results, but that takes some time to apply

This may be mitigated going forward. But even with noindex the engine has to re-learn/re-rank each new version page is what the user is looking for (based on search traffic).