updates planck default keymap

updating personal atomic keymap (#285)

Merge pull request #280 from Twey/master

Add `quantum/keymap_extras/keymap_plover.h` and a keymap.

Add Twey's keymap

adds voice iteration to planck default

Add a keymap_extras header for Plover

Fix typo (#276)

adds more voice harmonics

Merge remote-tracking branch 'origin/master'

# Conflicts:
#	quantum/audio/voices.c

adds fifth and fourth down voices

fixed compiler warnings (#273)

adds more voices, fixes macro redefines

Merge pull request #271 from eltang/qmk_firmware/eeprom_wear_fix

Update functions used to write to EEPROM

Update functions used to write to EEPROM

adds multiple voices and the ability to iterate/deiterate between them

Merge pull request #265 from sboesebeck/master

ErgodoxLayoutGenerator used

converts tabs to spaces

restructures audio, begins voicing

fade envelope

start of envelope function