Todo: Add Auto version increment

[thisRedH]

Add a Workflow, that automatically bumps the default Version.

• Version checking with fetching form Purpur Api see Docs
• Auto update README on GitHub and Docker-Hub
• Update in dockerfile
• Run Docker push with version x.x+1.x (e.g. 2.1.0 from 2.0.0) when Minecraft get a "minor" update, and x.x.x+1 (e.g. 2.0.1 from 2.0.0) if it gets a patch