Start with dask-expr doc build

[phofl]

• Closes #xxxx
• Tests added / passed
• Passes pre-commit run --all-files

This isn't ready to be merged, there are a couple of weird failures in the accessor docs

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

     15 files  ±0       15 suites  ±0   3h 10m 33s ⏱️ + 2m 43s
 12 983 tests ±0   12 053 ✅ ±0     929 💤 ±0  1 ❌ ±0 
160 174 runs  ±0  143 595 ✅  - 5  16 576 💤 +3  3 ❌ +2 

For more details on these failures, see this check.

Results for commit 1c6e54e. ± Comparison against base commit 1b711be.

♻️ This comment has been updated with latest results.

[phofl]

I've had to define a few accessors explicitly, since sphinx confused the DataFrame classes from Dask-expr and dask/dask without them. This is a known issue see sphinx-doc/sphinx#4961

[jrbourbeau]

Thanks @phofl -- overall this LGTM. I left a few comments, the main one I care about is the new API page being top-level in the DataFrame toc. All the other comments are just non-blocking suggestions.

[jrbourbeau]

It might be nice to add a few sentences here about the query planning effort and how to enable it. I don't mean this as a blocking comment -- we can always follow-up later, or not at all

[phofl]

Yes I intend to add content as we go before the new release is out

[jrbourbeau]

My sense is this is too top-level at the moment. I'd recommend moving this into the "Additional Information" dropdown for now unless there's a specific reason it needs to be top-level.

If it does need to be top-level, then we'll probably want more information about the query planning effort more generally that answers questions like "What is it?", "Why should I care?", "How do I enable it?", etc.

[phofl]

Yeah I'll move it down, but we ideally want to add the deprecation message soonish, would move it back up then, but we will hopefully have more content by then