improved documentation on key bindings overwrites

Author: Stephan Dilly

KEY_CONFIG.md

@@ -4,8 +4,20 @@ The default keys are based on arrow keys to navigate.
 
 However popular demand lead to fully customizability of the key bindings.
 
-On first start `gitui` will create `key_bindings.ron` file automatically based on the defaults.
-This file allows changing every key binding.
+Create a `key_bindings.ron` file like this:
+```
+(
+    focus_right: Some(( code: Char('l'), modifiers: ( bits: 0,),)),
+    focus_left: Some(( code: Char('h'), modifiers: ( bits: 0,),)),
+    focus_above: Some(( code: Char('k'), modifiers: ( bits: 0,),)),
+    focus_below: Some(( code: Char('j'), modifiers: ( bits: 0,),)),
+    
+    move_left: Some(( code: Char('h'), modifiers: ( bits: 0,),)),
+    move_right: Some(( code: Char('l'), modifiers: ( bits: 0,),)),
+    move_up: Some(( code: Char('k'), modifiers: ( bits: 0,),)),
+    move_down: Some(( code: Char('j'), modifiers: ( bits: 0,),)),
+)
+```
 
 The config file format based on the [Ron file format](https://github.com/ron-rs/ron).
 The location of the file depends on your OS:
@@ -14,6 +26,8 @@ The location of the file depends on your OS:
 * `$HOME/.config/gitui/key_bindings.ron` (linux)
 * `%APPDATA%/gitui/key_bindings.ron` (Windows)
 
+See all possible keys to overwrite in code: [here](https://github.com/extrawurst/gitui/blob/master/src/keys/key_list.rs#L83)
+
 Here is a [vim style key config](vim_style_key_config.ron) with `h`, `j`, `k`, `l` to navigate. Use it to copy the content into `key_bindings.ron` to get vim style key bindings.
 
 # Key Symbols