Remove WalletConnect Schema, point to ARC-25 instead

[jasonpaulos]

The current state
The page https://developer.algorand.org/docs/get-details/walletconnect/walletconnect-schema/ describes the Algorand WalletConnect schema.

The proposed state
Now that we have ARC-25 (https://arc.algorand.foundation/ARCs/arc-0025) which formalizes the schema, that page should just point to this ARC.

Provide any additional context
ARC-25 makes some minor changes to our schema, so we are showing out of date information on the docs site currently.