Add help command

[Ameer Jhan]

• We use a light weight cli tool called minimist and it does not come with support for help command, so we need to build a help command which provides info on available commands
• It should follow the same format as standard linux cli, for ex.

• Read the README.md to provide help on all commands

[dhruw]

I would like to work on this.

[Ameer Jhan]

@dhruwlalan sure

[Yash Joshi]

This has been released in v0.0.27 to npm. Thanks for helping us making blazepack better @dhruwlalan 🎉