It looks like from the history that some folks have just submitted a PR with a change to add to the listings there, we might do the same, or email Gnosis and ask the process.
This shouldn't happen until we're actually using our contracts on mainnet, so closing this and will make a note to revisit after a contract audit later next year.
Once our modules are set in stone we should submit details to Zodiac, to be listed in their Readme:
https://github.com/gnosis/zodiac
It looks like from the history that some folks have just submitted a PR with a change to add to the listings there, we might do the same, or email Gnosis and ask the process.