Finalise update script.

[TheCurle]

What

The goal for RetroGradle was to setup these projects automatically - have a shell script or Java file that you can feed a version number, and it will convert the whole program start to finish.

How

Our projects up to this point have all been leading us toward an automated pipeline.
In full, the tool needs to:

• Pull the MCP toolchain for that version
• Query the available MCP mappings for that version
• Adapt it to an MCPConfig version folder (RetroGradle/MCPConvert)
• Test and publish the MCPConfig artifacts to a local repository
• Generate an appropriate buildscript with the MCPConfig artifacts and mappings versions
• Set up the buildscript
• Test the buildscript (run the setup and runServer tasks)
• Notify of a completed run

This is a lot, and we're only at step 6 currently.