Prop 576: Add NOM/OSMO (#882) to External Incentive Matching program

Onomy's DAO has loaded a gauge for external incentives with the following parameters: 10K NOM over 90 epochs with a start time of 13th August 15:00 UTC. This proposal requests Osmosis to match Onomy's NOM incentives in OSMO. More details may be viewed here: https://forum.osmosis.zone/t/add-nom-osmo-882-to-external-incentive-matching-program/120