Add cheat sheets in image format with corresponding source in the relevant folder.

If there is a CSS Grid cheat sheet

• Save the image in assets folder of relevant directory
• Place the image link in SUMMARY.md with image original source
• Add Original Author's name (if applicable)

1. Fork the cheat-sheet repo and branch out from the default branch.
2. Read our guidelines
3. Add / Update the relevant files and commit them with a clear commit message
4. If you are creating a new page, don't forget to add an entry in the SUMMARY.md file of the main domain folder
5. Create a pull request in your fork to the default branch in the base repository
6. Link the issue of the base repository in your Pull request description.