added guide to create tokens with metadata using spl token CLI

[heyAyushh]

Problem

Token extensions have metadata builtin, hence wrote a guide on how you can create tokens using CLI and add metadata.

[mikemaccana]

@heyAyushh This was in Feb, but not merged - we have https://solana.com/developers/guides/getstarted/how-to-create-a-token now, which is also CLI based - should we merge this into that, taking the best bits?

I'd also use whimsical.com for the diagrams. I can help with that if needed.

[mikemaccana]

Closing per Ayush in Slack:

I think its better to close this pr then. We already have a doc covering it