Get rid of a couple of copies of the CC0 text. Add header comment to
CC0 files to remind people editing them what the terms are. Also add
some missing XML headers. The header comments in layouts won't bloat
the binary - they get stripped out before compressing, same as any other
comments.
Added support for 48k cartridges (e.g. LSEG-EDL v3.51)
Reorganized cart software lists, adding label information where available
Added tape and floppy software lists across all different systems
Added a few TODO notes based on my testing
Note: There is still lots of splitting to do in the TO-series lists.
