[DEV] Workflow Changes

[hypherionmc]

I want to implement the following workflow changes to this project:

• Add a dev branch, so all development work is not done on release. Releases to be triggered when pushing to release branch
• Add snapshot releases for dev branch so that they can be used/tested
• Sign releases with GPG - Will use keymaster
• Move secrets out of ENV variables and onto doppler - dopple

Long Term

• Publish releases to Gradle Plugin Portal