Updates vim_style_key_config.ron path

With commit #b0b37a8 vim style config path in KEY_CONFIG.md was unchanged

Author: irmantas

KEY_CONFIG.md

@@ -13,4 +13,4 @@ The location of the file depends on your OS:
 * `$XDG_CONFIG_HOME/gitui/key_config.ron` (linux using XDG)
 * `$HOME/.config/gitui/key_config.ron` (linux)
 
-Here is a [vim style key config](assets/vim_style_key_config.ron) with `h`, `j`, `k`, `l` to navigate. Use it to copy the content into `key_config.ron` to get vim style key bindings.
+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_config.ron` to get vim style key bindings.