Polish the doc for meter analyze and meter plugin for incoming plugin. (#5809)

docs/en/setup/README.md

@@ -56,6 +56,3 @@ Follow [backend and UI setup document](backend/backend-ui-setup.md) to understan
 ## Changes log
 
 Backend, UI and Java agent changes are available [here](../../../CHANGES.md).
-
-## Upgrade FAQ
-[6.x version upgrade FAQ](../FAQ/v6-version-upgrade.md) introduces the recommendation ways to do SkyWalking upgrade.

docs/en/setup/backend/backend-setup.md

@@ -110,6 +110,8 @@ to reflect the delegation in topology graph.
 1. [Apdex threshold](apdex-threshold.md). Configure the thresholds for different services if Apdex calculation is activated in the OAL.
 1. [Group Parameterized Endpoints](endpoint-grouping-rules.md). Configure the grouping rules for parameterized endpoints,
 to improve the meaning of the metrics.
+1. [Meter Analysis](backend-meter.md). Set up the backend analysis rules, when use [SkyWalking Meter System Toolkit](../service-agent/java-agent/README.md#advanced-features) 
+or meter plugins. 
 1. [Spring Sleuth Metrics Analysis](spring-sleuth-setup.md). Configure the agent and backend to receiver metrics from micrometer. 
 
 ## Telemetry for backend

docs/en/setup/backend/backend-ui-setup.md

@@ -43,6 +43,6 @@ Before deploying Skywalking in your distributed environment, you should know how
 - UI uses GraphQL (HTTP) query to access the backend also in Jetty service (`core/default/rest*` in `application.yml`).
 
 Now, let's continue with the backend, UI and CLI setting documents.
-- [Backend setup document](backend-setup.md)
-- [UI setup document](ui-setup.md)
-- [CLI set up document](https://github.com/apache/skywalking-cli)
+### [Backend setup document](backend-setup.md)
+### [UI setup document](ui-setup.md)
+### [CLI set up document](https://github.com/apache/skywalking-cli)

docs/en/setup/service-agent/java-agent/Supported-list.md

+# Tracing and Tracing based Metrics Analyze Plugins
+The following plugins provide the distributed tracing capability, and the OAP backend would analyze the topology and 
+metrics based on the tracing data.
+
 * HTTP Server
   * [Tomcat](https://github.com/apache/tomcat) 7
   * [Tomcat](https://github.com/apache/tomcat) 8
@@ -108,7 +112,12 @@
   * [Graphql](https://github.com/graphql-java) 8.0 -> 15.x
 * Pool
   * [Apache Commons DBCP](https://github.com/apache/commons-dbcp) 2.x
+  
+
+# Meter Plugins
+The meter plugin provides the advanced metrics collections, which are not a part of tracing.
 
+___
 ¹Due to license incompatibilities/restrictions these plugins are hosted and released in 3rd part repository, 
  go to [SkyAPM java plugin extension repository](https://github.com/SkyAPM/java-plugin-extensions) to get these.