fix: enhance docs

docs/v3/api-reference/endpoint/keys/create-key.mdx

@@ -7,4 +7,9 @@ Requires an admin key. On Honcho Cloud (`api.honcho.dev`) the returned key is a
 real cloud key on the calling key's instance, attributed to its owner and
 revocable from the [API Keys page](https://app.honcho.dev/api-keys). On a
 self-hosted instance it returns an error when `AUTH_USE_AUTH` is disabled.
+
+Provide at least one of `workspace_id`, `peer_id`, or `session_id` — a request
+carrying none of them is rejected. A key scoped to a peer or a session must also
+carry its `workspace_id`. On Honcho Cloud, pass either `admin=true` or a
+`workspace_id`.
 </Note>