[chore] fix continuous release not working correctly

[Titus-von-Koeller]

We should have a stable link that always gets updated! Since Matthew's change of GH action for the release mechanism, this has never worked as originally intendended.

So people can install directly from that link with pip install link and do that in their CI for example. The right link is already documented in our docs.

• get release update working again with stable links
• check the docs are in order relative to this
• make Unsloth and Axolotl folks aware of this functionality, as they expressed interest of using it in their CI