Add Devbuilds to spigotmc downloads

[SpellDigger]

buddy, most of us are broke and use aternos

so add the damn devbuild to spigotmc then u will stop seeing copies of the same issue that was fixed in a devbuild not everyone can download

i also need to devbuild for plugins to even work

[ineanto]

As far as I know, dev builds are development builds for a reason: they're not stable. We'll have to wait.