MAST-U mappings for the magnetics IDS

Connecting instructions to get mastu data with example

show toplevel globals

current status

who to contact

Things to include in the overview

Current data dictionary versions

Crucial things about the mappings (e.g flux_loop current, time, custom functions

The globals also need doing don't they, display those

To Adam,

Add comment as a footer which means I need to use the comments a little more :)