Fastapi-gae-logging

Dropped usage and dependency directly on FastAPI and replaced with Starlette instead. This way this package can be used with pure Starlette applications as well and even maybe with any other ASGI Starlette based frameworks that implement or inherit Starlette's `add_middleware` method for attaching pure ASGI middlewares.

Kudos to iffius for pointing that out!

- Polished some docstrings
- Loosened up dependencies on fastapi and google-cloud-logging

Dummy release to sync repo state with PyPi package state

- Added new parameter for opting-out payload logging in docstring
- Updated Readme to include definitions of API

- Added option to opt out for logging payload
- Updated readme with absolute image addresses to fix render in PyPi

Updated readme file to include screenshots with the effects of the module when viewing FastAPI app's logs in Google Cloud Log Explorer.