I'm not going to pile on in the GH issue, but I'll at least confirm that his reaction may have been a little over the top. You had good form on your PR and specifically mentioned the "feature request" nature of it.
To be fair, he looks to have had a pretty bad experience with other people doing in-line file changes straight from Github and trying to push them through as PR's (see the other open PR). He was probably just frustrated and lashing out. He needs a CONTRIBUTING.md in his root to explain his preferences.
From the original PR comment: "This pull request is a more of a feature request with proof of concept really."
It's definitely not the norm, but if it were my project I would appreciate the working example. You can pull that changeset into your own repo (probably another branch or something) from the command line and test it out without merging the PR.
To be fair, he looks to have had a pretty bad experience with other people doing in-line file changes straight from Github and trying to push them through as PR's (see the other open PR). He was probably just frustrated and lashing out. He needs a CONTRIBUTING.md in his root to explain his preferences.