Add prettier

[js0mmer]

Description

• Adds prettier and a husky precommit hook that calls lint-staged
• Next step would be to run formatting on the repo, otherwise there will be large diffs when reviewing PRs.
  • I think this would be better to implement in a separate PR, that way changes from this PR can be added to existing branches first which can help mitigate merge conflicts

Screenshots

Example commit

Steps to verify/test this change:

• Check out locally, npm install in root, then make a change and a test commit

Final Checks:

• Verify successful deployment
• Delete branch

(optional)

• Write tests
• Write documentation

Issues

Closes #370

[Awesome-E]

At least on MacOS, the hook doesn't run because it's not given executable permissions

[github-actions]

Deployed staging instance to https://staging-389.peterportal.org

[Awesome-E]

Formatting looks like it's working now!

I think one more thing just to be cautious of – since all commits will autoformat the entire file now, we should really make an effort to resolve the other PRs because any change to the same files will lead to lots of merge conflicts