Support for inline annotations from PEP 561 with py.typed but without .pyi

[kiwi0fruit]

From this issue #1190 it isn't clear if inline annotations from PEP 561 with py.typed file but without .pyiare supported by mypy.

If they are supported then please provide instruction what is need to make mypy use them (as I wasn't able to get them working). PyCharm supports them by the way.

If they are not supported then this is the issue to finally support them.

[ilevkivskyi]

Inline annotations are already supported, but PEP 561 packages must be installed if you want mypy to use them, see these docs and other docs for details.

[kiwi0fruit]

Thanks!