Type hints are not readily available through Pylance in VS Code

[RA80533]

Alternate title: "aioodbc does not support PEP 561"

PEP 561 – Distributing and Packaging Type Information defines the mechanisms for distributing packages with type hints:

Package maintainers who wish to support type checking of their code MUST add a marker file named py.typed to their package supporting typing. This marker applies recursively: if a top-level package includes it, all its sub-packages MUST support type checking as well.

Since aioodbc does not contain a py.typed marker file, developers may find themselves without any type hints for the package. Developers are unable to take advantage of the type annotations already part of the project.

Most typed packages on PyPI publish place their py.typed file in the namespace directory (e.g., "<root>/aioodbc") to better centralize the type checking to the package source code. It would be a huge improvement to the developer experience if the aioodbc project included a py.typed marker file alongside the package.

[jettify]

Yeah, py.typed missing because not everything typed, I was slowly moving that direction. Happy to accept any PRs.