[kreeben]

I like, nay, love, the fact the word "just" is so prominent in the description of your solution.

[slowhand09]

...considering building a "just" expander that shows all the steps required to "just" do anything.

[xkeysc0re]

I mean...it is just three steps involving some clicks and no code. I think that fits the bar for "just"

[mdaniel]

with the small asterisk that this mechanism only works for repos where one has sufficient privileges to be able to create a webhook, and that doesn't square up with the original title of "a file on GitHub"