Add guidance for wallets when using JsonSchemaCredential and selected disclosure

[andresuribe87]

From w3cping/privacy-request#119, point 2 says

When using CredentialSchema2023 with a Verifiable Credential that utilizes a selective disclosure proof suite, it may be possible for the verifier to determine additional attributes that would be available, but not presented when verifying a credential from the holder wallets. Wallets should be advised in a privacy section may want to reject these verification requests or selectively disclose the schema properties from the credential.

This issue is to track.