Enumerate services for counters

rfc/0084-app-service-level-telemetry.md

@@ -294,6 +294,14 @@ Where
   | `sdk_{service}_r_canceled` | Canceled |
   | `sdk_{service}_r_total` | Total number of operations. Note that this number might differ from `_count` of the histogram, if the response from the server has never been received. |
 
+  The `{service}` is one of the following:
+  * `kv`
+  * `query`
+  * `search`
+  * `analytics`
+  * `management`
+  * `eventing`
+
 * `{agent="couchbase-net-sdk/2.4.5.0 (clr/4.0.30319.42000) (os/Microsoft Windows NT 10.0.16299.0)",node="node1",node_uuid="91442eb8202e0e16bbb59624d9ccdb0a",bucket="travel-sample"}` is a list of the tags. The server is free to strip/transform any tags before relaying to Prometheus collector.
 
   | Label | Description |