Worker Versioning pre-release, v2

[drewhoskins-temporal]

What does this PR do?

This PR documents Worker Versioning, still pre-release

• Deprecate no-longer accurate docs.
• Point to README.md. We will come backfill real docs around public preview timeline.
• Some old docs are still relevant, so I've refreshed those.
• Refreshed version requirements based on changes that unlock this new version.

Notes to reviewers

Test plan

yarn start
http://localhost:3000/workers#worker-versioning
http://localhost:3000/develop/java/versioning#worker-versioning
http://localhost:3000/develop/python/versioning#worker-versioning
http://localhost:3000/develop/go/versioning#worker-versioning
http://localhost:3000/develop/typescript/versioning#worker-versioning

Click into links to make sure everything works.

[axfelix]

Hey @drewhoskins-temporal -- thanks for this contribution! One concern -- @rachfop and I had previously talked with the Worker Versioning team about how we were going to need to maintain the old Worker Versioning docs alongside the new ones for at least a little while, since everyone who's currently using the feature in preview still needs to know how the v1 API worked. As a result, we can't remove them entirely right now. Let me know if you want to discuss this synchronously or if we can start amending this PR to preserve the old docs alongside the new.