GitLab

* [ci] [docs] use mamba for readthedocs builds (fixes #4954)

* update docs

* simplify build script and add docs flag to gitignore

* exit with non-0 if build fails

* update CI job

* add doxygen

* remove outdated requirement_base.txt reference

* use conda create instead of conda env create

* fix conda create flags

* add nodefaults to env.yml

* Update docs/README.rst
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

* try to fix check-docs CI job

* additional changes

* switch from mamba to miniforge

* simplify docker command and fix issues in local build script

* Apply suggestions from code review
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

* update docs and conda

* Apply suggestions from code review
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>