Big sync

[doctorfree]

This is a very large pull request, over 100 commits. It's really too large to be a single pull request. I apologize.

I've merged cheat sheets from your repository with mine and a couple of other cheat sheet repositories. All are MIT licensed so the only restriction is retention of copyright notices.

The changes include:

• New cheat sheets
• Revised cheat sheets
  • Wiki style links are replaced with Markdown style links
  • Some expanded sections
  • Tags and links to other cheat sheets
  • CommonMark spec conformance
• Top level README and LICENSE
  • Added copyright notices for all authors
  • Combined README info

You may wish to selectively merge some of these changes and reject or modify others. Or, you may wish to ignore and close this pull request and ask me to submit others with more isolated changes easier to merge. I am ok with however you want to deal with it. I just wanted to get you my changes as my time will be shifted to another project for a while.

Anyway, it's cool what you have done and I wanted to contribute my work. I just am doing it in a clumsy manner due to time constraints. Feel free to pick and choose or toss. Thanks!

[doctorfree]

It looks like this pull request included my .github/FUNDING.yml which of course would be inappropriate for your repository.

Please ignore. My bad.

[ChristianLempa]

Wow, this is a lot. I need more time to review it.