Add types

[jd-solanki]

Is your feature request related to a problem? Please describe.
Dev community is loving the types and it also improves DX.

Describe the solution you'd like
Providing stub files for gspread package

Describe alternatives you've considered
None

Additional context
I am using mypy and getting this error 'Stub file not found for "gspread"'

[lavigne958]

Hi this is big subject for us, we already have a PR open about this.

I am working on it, it just takes time.

We currently have some circular dependencies that I need to solve, which implies to release a new major version of gspread.

It is currently planed for version 6.0.0

see issue #966

closing this issue.