The community decision-making procedures are detailed in the constitution - primarily, in sections 8 and 9. Although the emphasis is on trying to reach consensus wherever possible, there is a formal method (known as the "standard resolution procedure") described. This is based upon method used in Debian, which itself is based upon the Condorcet method (wikipedia page).
Although we don't have a formal software to run our voting system, there are many that exist - and there's even a git repository with a full Condorcet Voting Open Source Ecosystem Map. A couple of other useful/interesting links are: