YunoHost has an ‘Edit’ button on their homepage which lets you directly modify the content and send them a ‘patch’.
I wasn’t able to submit my change because of a ‘File not found’ error, but still find it fascinating to not require people to use GitHub or Git in order to contribute.
The logic is in the seemingly random ‘gertrude’ repository (which has not much of a README or description for what it is, and it looks like the ‘patch’ is just the full HTML page content; perhaps someone can manually integrate it later. They claim to require email verification to catch spam before actually sending the change.
If it was possible to put a mailto on the internet without spam, it could remove friction from this kind of collaboration and create steps for people to do larger things.