Update client metadata descriptions in VQL ref

docs/references/vql.yaml

@@ -898,6 +898,11 @@
     Client metadata is a set of free form key/value data. Artifacts
     may use this metdata or it may simply be used as part of your IR
     processes.
+
+    ### See also
+
+    - [client_set_metadata]({{< ref "/vql_reference/server/client_set_metadata/" >}}):
+      Sets client metadata.
   type: Function
   args:
   - name: client_id
@@ -916,18 +921,25 @@
   description: |
     Sets client metadata.
 
-    Client metadata is a set of free form key/value data (see
-    client_metadata() function).
+    Client metadata is a set of free form key-value pairs, i.e. a dict.
 
-    For existing keys, the value is overwritten. Setting a metadata
-    key with a `NULL` value deletes that entry.
+    When updating metadata the result is the same as adding 2 dicts.
+    For existing keys, the value is overwritten.
+
+    Setting a metadata key with a `NULL` value deletes that entry.
 
     ### Example
 
     ```vql
-    SELECT client_set_metadata(ClientId="C.1234", Foo="Bar")
-    FROM scope()
+    SELECT client_set_metadata(client_id=client_id, metadata=dict(department="Lab02"))
+    FROM clients()
+    WHERE os_info.hostname =~ "TRAINING"
     ```
+
+    ### See also
+
+    - [client_metadata]({{< ref "/vql_reference/server/client_metadata/" >}}):
+      Returns client metadata from the datastore.
   type: Function
   args:
   - name: client_id