Proposal: switch from `compilation-start` to `compile`

[Gastove]

Right now, compiling an Elm file with elm make is eventually run with compilation-start. I'd like to suggest switching to using compile; it does for free most of what compilation-start needs done manually, and it has the added advantage that it remembers your last command for use with recompile. So for instance -- if you C-u C-c C-c to start a compilation with a specified output, you can then recompile to run the same compilation over as needed (an advantage not shared with compilation-start).

I'm happy to PR this change if it's welcome!

[purcell]

Sounds reasonable at first glance, as long as elm-compilation-mode is still applied. My one concern is that recompile would not know to apply that mode, so the ANSI escape colourisation wouldn't work when recompiling.