Update MANIFEST.in

Author: sobolevn

Diff for: MANIFEST.in

@@ -5,6 +5,7 @@ recursive-include invoke/completion *
 recursive-include sites *
 recursive-exclude sites/*/_build *
 include dev-requirements.txt
+recursive-include * py.typed
 recursive-include tests *
 recursive-exclude * *.pyc *.pyo
 recursive-exclude **/__pycache__ *