Switch comment header to an h3

[j-f1]

The h1 header is very loud in the comment section at the moment. Netlify’s auto comments use an h3 instead of an h1 and it still draws attention without being too annoying.

[shiftkey]

Thanks for the contribution @j-f1. I'm going to leave this open for a bit to figure out why the test suite isn't passing (failures are highly likely to be unrelated to your change).

[j-f1]

It looks like since my PR comes from a fork the action isn’t allowed to post a comment. I encountered a very similar issue when integrating the check into a repo I help maintain and ended up swapping the workflow to a pull_request_target trigger but that wouldn’t work here since you presumably want to test any code changes.

[shiftkey]

Looks like this PR only has read access to pull requests, likely due to it coming from a fork as you mentioned.

These permissions seem fine though, perhaps we could run these jobs with a token that does have access to comment here (rather than jumping through all these GITHUB_TOKEN hoops):

webpack-bundlesize-compare-action/.github/workflows/test.yml

Lines 10 to 12 in 96f0beb

	permissions:
	contents: read
	pull-requests: write

[shiftkey]

Merging this in for now as I see #431 will also have the same issue