Add content for Connect to Starknet

[alexandratran]

Questions about get-starknet: Can we get more information about setting up and using get-starknet? The readme instructions don't really suffice.

• Do dapps still need to detect MetaMask and connect to MetaMask as usual, in addition to using the connect to Starknet wallet button?
• Can we have a full example of what this looks like in a simple dapp?
• How do devs/users access the functionality of the Starknet API methods that are rolled up in get-starknet?