Rasa: [Rasa Interactive] Suggested file paths needs to be updated from yml to md

[mprazz]

Rasa version:
Built from source on 2.0.x branch

Python version: 3.7.9

Operating system (windows, osx, ...): OSX

Issue:
These defaults need updating from .yml to .md, otherwise users will get an invalid path by entering the defaults

[tmbo]

@mprazz is someone already working on this? otherwise I'll create a PR

[tmbo]

(it's also the other way around, the defaults are correct and the validation needs to be adapted. but then at the same time the dumping actually needs to use the yaml format instead of the markdown one)

[mprazz]

I don't think anyone is on this @tmbo

[degiz]

@tmbo @mprazz I fixed it yesterday as a part of https://github.com/RasaHQ/rasa/pull/6914

[tmbo]

great work 🚀