This is entirely up to you, we don't force any distribution method on developers.
However, we do recommend listing them on the RapidWeaver Marketplace, this is a free service and allows your addons to be automatically marketed to the existing RapidWeaver user base.
Generally, you'll only need RapidWeaver and a text editor. Below are a collection of native tools for macOS you might find useful while developing addons for RapidWeaver.