Include type annotation marker file

[mtar]

Typed packages need to include a marker file to enable type checking support.

https://typing.readthedocs.io/en/latest/spec/distributing.html#packaging-type-information
https://typing.readthedocs.io/en/latest/guides/libraries.html#marking-a-package-as-providing-type-information

• Check if heat library is "type complete"
• include 'py.typed' file and update setup.py

[github-actions]

Branch features/1732-Include_type_annotation_marker_file created!

[github-actions]

This issue is stale because it has been open for 60 days with no activity.