Add a github release for 0.8.6

[joshka]

I understand that 0.8.6 is basically a noop, but Github releases automatically propagate to dependabot PRs (like joshka/xkcdwat#61). Adding a GitHub release for this would mean one less step to find out what changed in 0.8.6 for every developer that uses dependabot to update their deps.

[jplatte]

Sorry, I forgot to do this. I just made another patch release and wouldn't want 0.8.6 to show up after 0.8.7, is there a way to backdate the GH release? Otherwise I'd rather not.

[yanns]

I think that the order is using the creation date of the tag, but not 100% sure.