Fix and add some in README

Fix is_tap_key()

Add doc/keycode.txt

Add description of keymap and layer in README.md

Clean layer actions.

Add macro feature.

Add user defined function to action.

Add legacy keymap support.

Fix tapping. tap key just after tap timeout.

Fix: action LAYER_BIT uses xor now instead of and/or.

Fix process_tapping().

Clean debug print in action.c.

Clean code.

Add tap toggle feature to action.

Add oneshot modifier action.

Fix keycodes. It has 32 Fn keys now.

Remove test_func.

New tapping logic.

Minor fixes in keyboard.c.

Add prototype of Action Function.