Useful way to link to issues without a 'mentioned this issue' alert

[God-damnit-all]

I remembered you tried to do this in the past without success. After experimenting today, I discovered that adding 'www.' to a URL will keep GitHub from adding a 'mentioned this issue' alert. You can safely spoof the labels it auto-generates too, of course:

[#5](https://www.github.com/1480c1/media-autobuild_suite/issues/5) /
[1480c1/media-autobuild_suite#5](https://www.github.com/1480c1/media-autobuild_suite/issues/5)

#5 / 1480c1/media-autobuild_suite#5

As you can see from clicking on one and scrolling to the bottom, there's no mentioned in this issue alert. Handy!

[1480c1]

Interesting find, that feels like a weird oversight by github, but neat