Fix quick for autodoc2 render plugin

[lan496]

After merging #387, I have noticed auto summaries are generated in reStructuredText, not compatible with other myst documents.
https://spglib.readthedocs.io/en/latest/python-interface.html#version

This PR uses myst as autodoc2 render plugin and uses reStructuredText only for docstrings.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (50a2c3f) 83.86% compared to head (fc11efe) 83.86%.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #391   +/-   ##
========================================
  Coverage    83.86%   83.86%           
========================================
  Files           24       24           
  Lines         8180     8180           
========================================
  Hits          6860     6860           
  Misses        1320     1320           

Flag	Coverage Δ
c_api	77.59% <ø> (ø)
fortran_api	56.15% <ø> (ø)
python_api	80.38% <ø> (ø)
unit_tests	1.24% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[LecrisUT]

Weird, I wouldn't have expected it to affect that