This is an example Repository for a generic Slimefun4 Addon. In the top left is a button "Use this template", click this to create your own Addon for Slimefun4 using this basic template.

This is a template repository that you can use to create your own Slimefun4 Addon.
We have also written an extensive step-by-step tutorial which you can find here:
https://github.com/TheBusyBiscuit/Slimefun4/wiki/Developer-Guide

Navigate to src/main/java and rename the package and the .java File to your liking.
Suggestion: "me.yourname.yourproject" (all lower case) and "ProjectName.java"
Example: "me.thebusybiscuit.cooladdon" and "CoolAddon.java"

Navigate to src/main/resources/plugin.yml and change the "author" and "main" attributes. You may also want to change the description to something meaningful.

Navigate to pom.xml and change the group id to "me.%Your name%" and change the artifact id to the name of your Project.

After that you are good to go, you can now start developing your own Addon for Slimefun4.