Add documentation for `ubuntu` builder
Add documentation for `ubuntu` builder

popravich/vagga,joehillen/vagga,popravich/vagga,rrader/vagga,popravich/vagga,tailhook/vagga,KaminoDice/vagga,joehillen/vagga,rrader/vagga,rrader/vagga,KaminoDice/vagga,tailhook/vagga,tailhook/vagga,popravich/vagga,joehillen/vagga,joehillen/vagga,tailhook/vagga,KaminoDice/vagga