Add an contributor.md page to MyLA project

[zqian]

Thank you for contributing to this project!

Describe your problem or feature you'd like added

Many people made contributions to the MyLA project: UX design, user testing, communications, evaluation, etc. We would like to recognize all our contributors.

Describe the solution you'd like

I propose to use the "All Contributors" Open Spec. We will have an authors.md page and can use the @all-contributors bot 🤖 to automate acknowledging contributors to MyLA project.

Describe any possible alternatives you've considered

Additional context