Remove markdown log file support

[spbrogan]

Is your feature request related to a problem? Please describe.
Remove the markdown logger. This logger isn't being used and just wastes time in the logging path.

Describe the solution you'd like
Remove it

[Javagedes]

@spbrogan tianocore/edk2-pytool-extensions#373 has been created for this. Do you want the actual logging removed from edk2toollib?

[spbrogan]

Yes. I think we should. It had a lot of tentacles into logging so getting better aligned on python standard logging would be good.