Created COMMITTERS.md file

#8 earlier pull request, addressed all comments from there. 
Actually I just noticed, this new review is apparently a `COMMITTERS.md` file... I think I've been reviewing it thinking it was a `CONTRIBUTING.md` file. (it probably should be the latter still?)

In any case, I view this line as more both as a reminder (for me and other repo owners) to triage issues. But also as awareness for someone submitting an issue that triage will happen. (Kind of how we note that pull requests will be reviewed as a community).

Maybe: "Issues will be triaged and marked with an appropriate label (e.g. bug, enhancement, question)" then?