README improvements

Author: Mattia Roccoberton

README.md

@@ -119,10 +119,14 @@ Index:
 
 ![index](screenshot1.jpg)
 
-Edit (with `$form-padding: 2px;`):
+Edit:
 
 ![edit](screenshot2.jpg)
 
+Show - sidebar on the left:
+
+![edit](screenshot3.jpg)
+
 ## Contributors
 
 - [Mattia Roccoberton](http://blocknot.es) - creator, maintainer