[Good first issue]: Set up all-contributors bot

[edwardchalstrey1]

Add the all-contributors bot which will automatically pull a contributing GitHub user's profile, grab the contribution type emoji, update the project README and then open a Pull Request against the project.

[tanav8570]

I would like to work on this!
I've recently submitted a PR regarding LaTeX character escaping and noticed this issue was still open. I can handle the initial setup of the .all-contributorsrc file and the necessary README.md tags to get the bot running.