The footnote is that I didn't author the idea of gaps in i3. There used to be a loose patch floating around that applied to an old version of i3.
When I came to Linux I quickly got into the unixporn community. After a bit of making Ubuntu look nice, I discovered i3. I then found the gaps patch and rebased it onto the latest version of i3 at the time. Lots of unixporn people liked that and asked me to create a repository for it, so I did -- and i3-gaps was born.
The reason I say it's true enough to say it was born on unixporn is that it's where "a gaps patch" turned into "i3-gaps", and also I reworked so much of that initial small patch that it became something new essentially.