[WARNING] Removing the demo app also removes files that do not belong to the demo app

[mmvcode]

Describe the bug
I thought I would give this package a shot, so I installed everything, including the demo app. I thought it was nice and I started doing some things, without removing the demo app. Then, I thought maybe I should remove that demo app, don't need it anymore. Unfortunately I did not version any of the work beforehand. I ran the command npm run remove-demo and ...bam, all the files are gone :)). I think that there removal script should either delete only the specific files it had and also check if they have been changed and warn the user or there should be a warning in the documentation and to the command that this will happen.

To Reproduce
Steps to reproduce the behavior:

1. Check out and install
2. Add new files to components, constants, etc
3. Run the npm run remove-demo
4. Files are gone

Expected behavior
Warning to user or only deleted unchanged demo app files

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: MacOS Catalina
• Browser: irrelevant
• Version Latest