Fix wrong references to doc files in .gitignore

Author: molinav

.gitignore

@@ -33,7 +33,7 @@ Thumbs.db
 
 # Things specific to this project.
 *.pickle
+doc/build
 doc/examples/*.png
-doc/users/installing.rst
-doc/_static/matplotlibrc
-doc/_templates/gallery.html
+doc/source/_static/matplotlibrc
+doc/source/_templates/gallery.html