Add Markdown Previewer Project

[airscripts]

Is your feature request related to a problem? Please describe.
As of now I have a repository for every project into freeCodeCamp's curriculum that I want into one single repository.

Describe the solution you'd like
Merge the related repository into campfire.
The repository can be found here: https://github.com/Airscripts/fcc-markdown-previewer.

Describe alternatives you've considered
/

Additional context
How to do it correctly:

1. Fork this project and then clone the repository on your machine;
2. Run the following commands in sequence:

cd campfire
git pull origin main
git remote add -f project-name link-to-project
git switch -c new-branch-name
git merge project-name/main --allow-unrelated-histories
git rebase -i main

3. Move the merged project into campfire/curriculum/front-end-development-libraries;
4. Commit changes;
5. Push and open pull request.

[elgorditosalsero]

Yo

This command is wrong for fcc-markdown-previewer as is not

git merge project-name/master --allow-unrelated-histories

but

git merge project-name/main --allow-unrelated-histories

[airscripts]

Gotcha! Thanks!