DEV: update RESP2/3 annotation (#1553)

Author: dwdougherty

content/develop/reference/protocol-spec.md

@@ -50,8 +50,9 @@ In Redis 2.0, the protocol's next version, a.k.a RESP2, became the standard comm
 Redis 6.0 introduced experimental opt-in support of RESP3's features (excluding streaming strings and streaming aggregates).
 In addition, the introduction of the [`HELLO`]({{< relref "/commands/hello" >}}) command allows clients to handshake and upgrade the connection's protocol version (see [Client handshake](#client-handshake)).
 
-Up to and including Redis 7, both RESP2 and RESP3 clients can invoke all core commands.
+From Redis version 7 and forward, both RESP2 and RESP3 clients can invoke all core commands.
 However, commands may return differently typed replies for different protocol versions.
+Each command has descriptions of RESP2 and RESP3 return values that you can reference.
 
 Future versions of Redis may change the default protocol version, but it is unlikely that RESP2 will become entirely deprecated.
 It is possible, however, that new features in upcoming versions will require the use of RESP3.