Update docs to reference host-support for jaeger-query

docs/opentelemetry.md

@@ -12,12 +12,18 @@ To try this out:
 
 You should now see that the /tmp/trace file is created.
 
-Then we have an experimental tool to serve the trace file to jaeger:
+Then we have an experimental tool to serve the trace file to jaeger. First ensure `jaeger-query` is in your PATH, available [here](https://www.jaegertracing.io/download/#binaries)
 
 ```
 cd tools/otel/traceserver
 go run . --src /tmp/trace --run jaeger
 ```
 
+Alternatively you can use the jaeger docker image with:
+
+```
+go run . --src /tmp/trace --run docker-jaeger
+```
+
 Not everything is instrumented yet, and not all the traces are fully joined up (we need to thread more contexts through more methods),
 but you should be able to start to explore the operations that we run and their performance.