Extended and converted user guide to ReST

Restructured text provide more options to extend the documentation by
including sphinx generated content.

Also added reference documentation for the static configuration format.

Signed-off-by: Claudius Heine <ch@denx.de>

docs/conf.py

@@ -41,6 +41,7 @@ extensions = [
     'sphinx.ext.coverage',
     'sphinx.ext.viewcode',
     'sphinx.ext.githubpages',
+    'sphinxarg.ext',
 ]
 
 # Add any paths that contain templates here, relative to this directory.