Move config.json to config.json.sample

This makes it easier to have your own config.json and don't lose changes/get
conflicts if you update directly from the repository

Author: mathias-baumann-sociomantic

README.rst

@@ -25,7 +25,9 @@ Dependencies
 Setup
 =====
 
-You can configure what the application does by changing ``config.json``:
+You can configure what the application does by changing copying the sample
+config file ``config.json.sample`` to ``config.json`` and changing it to your
+needs:
 
 ::