Bump sphinx-click from 2.3.0 to 2.3.1 in /docs

Bumps [sphinx-click](https://github.com/stephenfin/sphinx-click) from 2.3.0 to 2.3.1.
- [Release notes](https://github.com/stephenfin/sphinx-click/releases)
- [Commits](click-contrib/sphinx-click@2.3.0...2.3.1)

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

docs/requirements.txt

@@ -3,7 +3,7 @@
 
 sphinx==2.2.1
 sphinx_autodoc_typehints==1.10.3
-sphinx-click==2.3.0
+sphinx-click==2.3.1
 recommonmark==0.6.0
 m2r==0.2.1
 tomlkit==0.5.8