Update tempo docs (#704)

* Update tempo docs

content/en/docs/Configuration/p8s-jaeger-grafana/_index.md

@@ -1,5 +1,5 @@
 ---
-title: "Prometheus, Jaeger, Grafana"
+title: "Prometheus, Tracing, Grafana"
 description: "Kiali data sources and add-ons."
 ---
 

content/en/docs/Configuration/p8s-jaeger-grafana/tracing/tempo.md

@@ -9,10 +9,10 @@ weight: 2
 
 There are two possibilities to integrate Kiali with Grafana Tempo:
 
-- Using the Tempo API: This option returns the traces from the Tempo API in OpenTelemetry format. 
+- Using the Grafana Tempo API: This option returns the traces from the Tempo API in OpenTelemetry format. 
 - Using the Jaeger frontend with the Grafana Tempo backend.
 
-### Use Tempo API 
+### Using the Grafana Tempo API 
 
 This is a configuration example to setup Kiali tracing with Grafana Tempo: 
 
@@ -23,18 +23,36 @@ spec:
       # Enabled by default. Kiali will anyway fallback to disabled if
       # Tempo is unreachable.
       enabled: true
-      # Jaeger service name is "tracing" and is in the "telemetry" namespace.
+      # Tempo service name is "query-frontend" and is in the "tempo" namespace.
       # Make sure the URL you provide corresponds to the non-GRPC enabled endpoint
-      # if you set "use_grpc" to false.
-      in_cluster_url: "http://tracing.telemetry:3200"
+      # It does not support grpc yet, so make sure "use_grpc" is set to false.
+      in_cluster_url: "http://query-frontend.tempo:3200"
       provider: "tempo"
-      use_grpc: true
-      # Public facing URL of Grafana with the Tempo Datasource 
-      # Note this is not fully integrated 
-      url: "http://my-tempo-host/explore?left=%7B%22datasource%22:%22Tempo%22,%22queries%22:%5B%7B%22refId%22:%22A%22,%22queryType%22:%22traceId%22,%22query%22:%22%22%7D%5D,%22range%22:%7B%22from%22:%22now-1h%22,%22to%22:%22now%22%7D%7D&orgId=1"
+      use_grpc: false
+      # Public facing URL of Grafana 
+      url: "http://my-tempo-host:3200"
 ```
 
-### Use Jaeger frontend with Grafana Tempo tracing backend
+The default UI for Grafana Tempo is Grafana, so we should also set the Grafana url in the configuration: 
+
+```yaml
+spec:
+  external_services:
+    grafana:
+      in_cluster_url: http://grafana.istio-system:3000
+      url: http://my-grafana-host
+```
+
+We also need to set up a default [Tempo datasource](https://grafana.com/docs/grafana/latest/datasources/tempo/) in Grafana. 
+
+![Kiali grafana_tempo](/images/documentation/configuration/grafana_tempo_ds.png)
+
+To improve performance, the data of each Trace is not complete until we hover in that specific trace. Because all the trace information is not
+complete in advance, the total number of spans is unknown, and all the traces are represented in the graph with the same size. 
+
+![Kiali grafana_tempo](/images/documentation/configuration/grafana_tempo.png)
+
+### Using the Jaeger frontend with Grafana Tempo tracing backend
 
 It is possible to use the Grafana Tempo tracing backend exposing the Jaeger API.
 [tempo-query](https://github.com/grafana/tempo/tree/main/cmd/tempo-query) is a