Add converted (and slightly edited) documentation.

Based on the work of Shlok Inani as part of CCI.

admin_manual/conf.py

@@ -25,7 +25,8 @@ import sys, os
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = []
+extensions = ['sphinxcontrib.phpdomain', 'sphinx.ext.todo']
+
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['../_shared_assets/templates']