Revert "Ignore html/doctrees"

This reverts commit 2d3f4f3d870f10c94fc9e61bc0d144854d625198.

.gitignore

@@ -18,8 +18,6 @@ celerybeat-schedule
 /env
 /node_modules/
 /docs/_build
-/docs/html
-/docs/doctrees
 example/db.sqlite
 /src/sentry/static/sentry/dist/
 /src/sentry/static/sentry/vendor/