docs: update README.md, add different keyboard configurations #3

Job	Run time
build / Fetch Build Keyboards	7s
build / Build (nice_nano_v2, corne_left, corne_left)	1m 54s
build / Build (nice_nano_v2, corne_right, corne_right)	1m 36s
build / Build (nice_nano_v2, settings_reset)	1m 19s
build / Build (nice_nano_v2, corne_left, -DKEYMAP_FILE=../../config/corne.keymap -DEXTRA_CONF_FILE=../../...	1m 51s
build / Build (nice_nano_v2, corne_right, -DKEYMAP_FILE=../../config/corne.keymap -DEXTRA_CONF_FILE=../.....	1m 33s
build / Build (nice_nano_v2, corne_left, -DKEYMAP_FILE=../../config/corne.keymap -DEXTRA_CONF_FILE=../../...	1m 36s
build / Build (nice_nano_v2, corne_right, -DKEYMAP_FILE=../../config/corne.keymap -DEXTRA_CONF_FILE=../.....	1m 33s
build / Build (nice_nano_v2, corne_left, -DKEYMAP_FILE=../../config/corne.keymap -DEXTRA_CONF_FILE=../../...	1m 37s
build / Build (nice_nano_v2, corne_right, -DKEYMAP_FILE=../../config/corne.keymap -DEXTRA_CONF_FILE=../.....	1m 33s
build / Build (nice_nano_v2, corne_left, -DKEYMAP_FILE=../../config/corne.keymap -DEXTRA_CONF_FILE=../../...	1m 52s
build / Build (nice_nano_v2, corne_right, -DKEYMAP_FILE=../../config/corne.keymap -DEXTRA_CONF_FILE=../.....	1m 33s
build / Merge Output Artifacts	4s
	18m 8s

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