feat: update existing comments if they exist

[castastrophe]

This update relates to issue #7 to update existing comments in a pull request on subsequent runs. In larger repos, this will reduce the amount of comments being added to a PR during its review cycle.

[Dunklas]

Thank you so much for opening this PR! 🙌🏼
In general I think it looks great, but I had some problems while actually running it - Left a comment about that.
Looking forward to have this merged once that issue is resolved! 🚀

[castastrophe]

@Dunklas Just pushed up the updates based on the review. Thanks for taking the time to look at this!

[Dunklas]

Thanks a lot! It looks great, but I'm still having issues running it. Still getting Error: Unhandled error: TypeError: comments.reverse is not a function. Have you managed to run it successfully? Not sure if you're aware, but you can try out your changes by using something like below in a workflow.

steps:
      - uses: castastrophe/workflow-timer@cc2290f58b804c1de5b213d23f4faa678fe5ff54

Once we get this merged I think I'll look into introducing some typescript and tests in this project, then it'll be a bit easier to catch things like this. Writing code in a yaml-file isn't optimal :)

[Dunklas]

@castastrophe Just want to check if you still want to continue on this? I think it'd be a great addition! :)
I think all that's needed is to invoke reverse on the data property of comments.