Bump sphinx-rtd-theme from 1.0.0 to 2.0.0

Bumps [sphinx-rtd-theme](https://github.com/readthedocs/sphinx_rtd_theme) from 1.0.0 to 2.0.0.
- [Changelog](https://github.com/readthedocs/sphinx_rtd_theme/blob/master/docs/changelog.rst)
- [Commits](readthedocs/sphinx_rtd_theme@1.0.0...2.0.0)

---
updated-dependencies:
- dependency-name: sphinx-rtd-theme
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

docs/requirements.txt

@@ -1,5 +1,5 @@
 alabaster==0.7.12
 Sphinx==5.1.1
-sphinx-rtd-theme==1.0.0
+sphinx-rtd-theme==2.0.0
 sphinx-copybutton==0.5.1
 importlib-metadata; python_version < '3.8'