Add pre-commit hook that fails if committing the playground

[dbowling]

Most of the time, the playground html file should not be committed if modified. We should add some sort of linting to the pre-commit step that fails the commit if a change is made. Developers can ignore checks to get changes to this one file through.

[dbowling]

Quick update on where this issue is at:

POC exists using Husky to trigger but the shell script needs refactoring to use portable shell commands, rather than test logic that only works in the zsh environment. The logic requires some evaluation that I'm just not familiar with writing cross-environment.

Currently on the back-burner, but just needs a little research to push over the line.