#421 added config file support

[vinitparekh17]

This PR resolves the issue #421

1. sub-command: init-config

Usage:

go run main.go init-config

it will generate default config file at /etc/dice/dice.conf

2 load your config file located anywhare

go run main.go -c <path-to-your-dice.conf>

[!NOTE] Since default location of config file is /etc/dice/dice.conf so we have to start DiceDB with appropriate permission to create and read config file.