Add markdown support to docs

docs/Dockerfile

@@ -1,5 +1,5 @@
 FROM python:3.6
 
 RUN apt-get update && apt-get install -y graphviz
-RUN pip install sphinx livereload sphinx_rtd_theme django-environ django
+RUN pip install sphinx livereload sphinx_rtd_theme django-environ django myst-parser
 WORKDIR /app/docs

docs/conf.py

@@ -46,7 +46,7 @@ for key, value in FUNKWHALE_CONFIG.items():
 # Add any Sphinx extension module names here, as strings. They can be
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
-extensions = ["sphinx.ext.graphviz", "sphinx.ext.autodoc"]
+extensions = ["sphinx.ext.graphviz", "sphinx.ext.autodoc", "myst_parser"]
 autodoc_mock_imports = [
     "celery",
     "django_auth_ldap",