Show using snforge_std and sncast_std from registry in docs

[cptartur]

In various places in documentation, we show using snforge_std and sncast_std from git. We should instead show how to use them from package registry.

[Mystic-Nayy]

@cptartur Please can I be assigned to work on this?
I am a smart contract developer and also a technical writer, I can handle this.

[od-hunter]

Hi @cptartur , please can I be assigned this?
I am a blockchain developer and I'm also good at documentations. Below are some of the documentations I've done that were merged:

dojoengine/book#308,

keep-starknet-strange/joyboy#143,

Scaffold-Stark/ss2-docs#31,

horuslabsio/Starknet-Scaffold#94,

Hyle-org/examples#15,

Please I’m ready to work, assign me please.

[martinvibes]

hello @cptartur i would love to work on this issue please kindly assign :)

i'm a blockchain dev and a technical writer and would love to contribute to this repo