URLs no longer include minor version

In this case, I think it's down to how the branch was created. We can change "10" for "10.0.x". I think this is just content change (and then perhaps reindexing/reparsing) that @drumm can do.

This is a new change. The parsing and navigation for every minor version at the current cadence of core releases was getting unmanageable. We do want to be specific about what documentation you are viewing; updating to parse 10.4 instead of 10.3 is a manual process, and will remain at the same URLs.

The most minor versions we could keep would be something like keeping the last ~3, or keeping them all until the next major version is released. However, then the minor-version-specific URLs would regularly be removed and more cumbersome to maintain. Having the URLs be the same for the whole major release cycle keeps more URLs at the same place.

I think that’s not worth it right now since:

• APIs should be backward-compatible in each minor version.
• Minor version updates for sites should be within reach to upgrade when you find a need to, including for using new APIs.
• The in-code documentation can mention when changes and additions were made.