Update docs.ex

Author: josevalim

lib/mix/tasks/docs.ex

@@ -341,12 +341,14 @@ defmodule Mix.Tasks.Docs do
 
   ## Changing documentation over time
 
-  As your project grows, your documentation may very likely change, even structurally. There are a few important things to consider in this regard:
-
-  - Links to your *extras* will break if you change or move file names.
-  - Links to your *modules, and mix tasks* will change if you change their name.
-  - Links to *functions* are actually links to modules with anchor links. If you change the function name, the link does
-  not break but will leave users at the top of the module's documentation.
+   As your project grows, your documentation may very likely change, even structurally.
+  There are a few important things to consider in this regard:
+
+    * Links to your *extras* will break if you change or move file names.
+    * Links to your *modules, and mix tasks* will change if you change their name.
+    * Links to *functions* are actually links to modules with anchor links.
+      If you change the function name, the link does not break but will leave users
+      at the top of the module's documentation.
 
   Because these docs are static files, the behavior of a missing page will depend on where they are hosted.
   In particular, [hexdocs.pm](https://hexdocs.pm) will show a 404 page.