Add documentation on token argument

[IanPhilips]

the dao install requires a third app-init-args: the array of accepted tokens.

Here is an example:
--app-init-args 0xae1dcb3feca1f831a97f4e68d49a120f739eff81 0xdc39bd1f597e89db4a806d57ba8f4811396a66ba ["'0x24be0Eb6D8d492b2BdD8A40e1AC8E374bb09A222'"]

NOTE: the accepted token must have double quotes outside and single quotes for each token address in format: [" '<token_address', 'token_address_2' "]