Fix indentation of options in mix format

Author: josevalim

lib/mix/lib/mix/tasks/format.ex

@@ -104,11 +104,11 @@ defmodule Mix.Tasks.Format do
 
   The `opts` passed to `format/2` contains all the formatting options and either:
 
-      * `:sigil` (atom) - the sigil being formatted, e.g. `:M`.
+    * `:sigil` (atom) - the sigil being formatted, e.g. `:M`.
 
-      * `:modifiers` (charlist) - list of sigil modifiers.
+    * `:modifiers` (charlist) - list of sigil modifiers.
 
-      * `:extension` (string) - the extension of the file being formatted, e.g. `".md"`.
+    * `:extension` (string) - the extension of the file being formatted, e.g. `".md"`.
 
   Now any application can use your formatter as follows: