Documentation : layout

Different layouts are included by modifying a variable in the makefile.

To write a new one:

You must implement everything defined in [layout.h] (layout.h). Take a look at existing layouts in the 'layout' subdir.
- Currently, see [qwerty.c] (layout/qwerty.c) and [qwerty.h] (layout/qwerty.h). The latter is only important if you want more than one layer. And I still need to write the functions to make that possible (though that shouldn't be hard, I just haven't gotten to it yet). But (at least for the QWERTY and Dvorak layouts I'd really like to include) if you indicate it clealy in the layout, and provide complete initializations for kb_layout[][][], kb_layout_press[][][], and kb_layout_release[][][], I'll make sure it gets working.
The number of layers must be defined in the layout *.h file.
Use 0 for no-operation (unused) keys, and NULL for no-operation (unused) functions.
See [matrix.md] (matrix.md) for how the key matrix maps to hardware.
See [keyboard-usage-page--short-names.h] (../../lib/_usb/keyboard-usage-page--short-names.h) for available keycodes.
See [key-functions.c] (../../key-functions.c) for what functions keys can call.

notes

Assuming 560 bytes for everything else in RAM space, there's 2000 bytes left for the layout. This should be enough for about 7 layers. Watch your RAM usage if you're getting close.
- The layout matricies could be moved to flash memory (program space, instead of data space) in order to save RAM, but that doesn't seem necessary at the moment. It would also be slightly slower, though that probably shouldn't be a concern. It might be necessary (or convenient) if one were trying to implement on-keyboard remaping.