After the changes in MOTOR-602, motor's docs will build with Sphinx 4 without errors or warnings. Unfortunately, various api methods are no longer rendered in the resulting docs. For example, aggregate, aggregate_raw_batches, find, find_raw_batches, and other important methods are completely missing.

In order to upgrade to Sphinx 4 (or even Sphinx 3) we'll need to fix this issue. This issue was noticed while working on MOTOR-745.