Add support to Markdown Footnotes

[tjapro]

Description

The results of beautification are not what I expect.

Input Before Beautification

This is what the code looked like before:

blabla[^1]
[^1]: footnote blabla

Expected Output

The beautified code should have looked like this:

blabla[^1]
[^1]: footnote blabla

Actual Output

The beautified code actually looked like this:

blabla[^1]
[^1]]: footnote blabla

Steps to Reproduce

1. Add code to Atom editor
2. Open a .md file with footnotes
3. Run command Atom Beautify: Beautify Editor
4. This beautified code does not look right!

Debug

See https://github.com/remarkjs/remark/issues/486

Here is a link to the debug.md Gist: https://gist.github.com/TJProgrammer/a15408da00a098e724f1ffe559e1d576

Checklist

I have:

• [x] Tried uninstalling and reinstalling Atom Beautify to ensure it installed properly
• [x] Reloaded (or restarted) Atom to ensure it is not a caching issue
• [x] Searched through existing Atom Beautify Issues at https://github.com/Glavin001/atom-beautify/issues so I know this is not a duplicate issue
• [x] Filled out the Input, Expected, and Actual sections above or have edited/removed them in a way that fully describes the issue.
• [x] Generated debugging information by executing Atom Beautify: Help Debug Editor command in Atom and added link for debug.md Gist to this issue

[tjapro]

Some thoughts about this?