Ignore dynamically generated doc/tags

[ghost]

I'm ignoring the dynamically generated doc/tags file to avoid having my submodule dirty all the time.

[tonylambiris]

Please merge, I always get a dirty submodule with GoldenView

16:35:11 c1-linuxdev ((ac0ee30...)) ~/.vim/bundle/GoldenView $ git status
HEAD detached at ac0ee30
Untracked files:
  (use "git add <file>..." to include in what will be committed)

	doc/tags