Moves the bulk of apheleia.el into a new apheleia-core.el file and move
formatter definitions and mode-associations into a new
apheleia-formatters.el file. The end user experience should be
unchanged. Loading `apheleia.el` will still load everything load
everything, just like it used to.
* feat: add phpcs & introduce scripts/formatters
Add phpcs as a supported formatter, and include support for
apheleia-defined scripts for more troublesome formatters
* Revert Emacs version requirement
* More quoting
* Adjust language in documentation
* Thanks checkdoc, lol
Co-authored-by: Radon Rosborough <radon.neon@gmail.com>
