doc(preconf): Only (un)comment needed

doc/vimmic.txt

@@ -128,12 +128,15 @@ You can also disable plugins with the `disable.toml` file using the same syntax.
 
 The optional `$VIMMIC_DIR/.vimrc.preconf` file allows to
 change some configuration that needs to be applied 'a priori',
-like shown in the `extra/` folder.
+like shown in the `extra/` folder. For use, you can just copy paste this
+sample file and comment / uncomment lines.
 
 It lets you disable some features of the configuration:
 - `let g:disable_defaultColors =1`            		"disables all theming colors and words highlight defined
 - `let g:disable_highlightWordUnderCursor =1` 		"disables the current word highlight
 - `let g:disable_margin =1`                   		"disable the 120 characters margin
+- Status line theme related colors
+- ...
 
 Also, use this file if you want to change you default leader key.