Mark packages as typed

[jooola]

Describe the bug

Mypy is failing because the packages aren't marked as typed (missing py.typed file), but it seems that most of the packages have the type definitions.

Could the packages be marked as typed ?

To Reproduce

from testcontainers.compose import DockerCompose

with DockerCompose("."):
 pass

$ mypy tests
tests/e2e_test.py:12: error: Skipping analyzing "testcontainers.compose": module is installed, but missing library stubs or py.typed marker [import]
tests/e2e_test.py:12: note: See https://mypy.readthedocs.io/en/stable/running_mypy.html#missing-imports

[tillahoffmann]

Yes, that should definitely be possible. Would you be up for setting up a PR? We could also add mypy checks in the same PR.

[alexanderankin]

@jooola if you have any feedback about #504 it is welcome!