docs: `mdformat` description

### Overview

We need a description for the `mdformat` tool used for format markdown files: what it does, how it compares to markdown lint, how to setup and use it with an example.
### Action Items

- [ ] create mdformat.md page in tools/
- [ ] write description
- [ ] what it does
- [ ] how it compares to markdown lint
- [ ] how to setup and use it
- [ ] add example to format a file
- [ ] add example to run it in pre-commit

### Resources/Instructions

- [mdformat repo](https://github.com/executablebooks/mdformat)
- [mdformat-mkdocs repo](https://github.com/KyleKing/mdformat-mkdocs)
- our [pre-commit page](http://localhost:8005/contributing/tools/pre-commit/#installation) - may need to fix link