Suggest fixits

[ZedThree]

Closes #4

Uses the --export-fixes argument to read in a yaml file of fixes, which are more easily turned into github suggestions.

[ZedThree]

This works, but there's still some hard-to-use bits that need ironing out. If a line needs changing in multiple places, it currently comes out as separate suggestions:

which github won't let you apply in a single commit (easily).

So I need to work out how to squash them into a single suggestion

[ZedThree]

Almost complete, now need to handle the "Notes" attributes, which can appear when expanding a macro for instance