doc: the typo train

Context

NB: This edition has been merged. Next edition of the typo train: !3317 (merged)

This is the current edition of the typo train, an MR batching minor modifications to the doc, such as fixing typos or RST syntax elements, eliminating inconsistencies, etc.

It mainly contains:

• fixes for various Sphinx and Odoc errors and warnings
• a fix for the incorrect rendering of bullet lists everywhere. This is due to MR !3290 (merged) which upgraded sphinx-rtd-theme to 0.5.1, that (fixes the search feature in the doc but) uses a buggy docutil version 0.17. The current solution is to upgrade sphinx-rtd-theme to 0.5.2, which downgrades docutil to version 0.16.

Manually testing the MR

Check that the modifications correspond to the criteria above, and they are right. Then build the doc, check the errors/warnings and the result.

Checklist

• Select suitable reviewers using the Reviewers field below.