Google Code-in

This task is to search around the wiki, the developers guide and the implementers guide to find pages mentioning old instructions for publishing to modules.openmrs.org and point to https://wiki.openmrs.org/x/zIMmAQ instead.

Also any mentioning of the modules.openmrs.org url should be replaced with the addons.openmrs.org url. Modules.openmrs.org will continue to work, but it will redirect to addons.openmrs.org, which should be the preferred way to access it. I'd like to review any edits you make, so please post them under this issue in comments.