Create emacs package for fawltydeps

[obscurerichard]

Is your feature request related to a problem? Please describe.
A large proportion of the the worldwide developer population uses emacs to write Python, and could benefit from FawltyDeps package.

Describe the solution you'd like
Create an emacs package that executes FawltyDeps, much as existing packages for other linters (black, isort, etc) do.

Describe alternatives you've considered
Create a Visual Studio Code plugin (see #434 )
Create CI plugins (see #170)

Additional context
This was contemplated in the original design document for FawltyDeps but not added to the backlog.