[docs] Add documentation todos.

llvm-svn: 154276
diff --git a/lld/docs/conf.py b/lld/docs/conf.py
index 815d5ae..bb3ee8f 100644
--- a/lld/docs/conf.py
+++ b/lld/docs/conf.py
@@ -248,4 +248,4 @@
 # -- Options for extensions ----------------------------------------------------
 
 # Enable this if you want TODOs to show up in the generated documentation.
-#todo_include_todos = False
+todo_include_todos = True