[improve][doc] Improve Pulsar function document (#20073)

diff --git a/distribution/server/src/assemble/bin.xml b/distribution/server/src/assemble/bin.xml
index 12c443d..92aef62 100644
--- a/distribution/server/src/assemble/bin.xml
+++ b/distribution/server/src/assemble/bin.xml
@@ -116,6 +116,11 @@
       <destName>example-window-function-config.yaml</destName>
       <outputDirectory>examples</outputDirectory>
     </file>
+    <file>
+      <source>${basedir}/../../pulsar-functions/java-examples/src/main/resources/example-stateful-function-config.yaml</source>
+      <destName>example-stateful-function-config.yaml</destName>
+      <outputDirectory>examples</outputDirectory>
+    </file>
   </files>
   <dependencySets>
     <dependencySet>
diff --git a/pulsar-functions/java-examples/src/main/resources/example-function-config.yaml b/pulsar-functions/java-examples/src/main/resources/example-function-config.yaml
index a66b75f..1f185a2 100644
--- a/pulsar-functions/java-examples/src/main/resources/example-function-config.yaml
+++ b/pulsar-functions/java-examples/src/main/resources/example-function-config.yaml
@@ -22,9 +22,6 @@
 name: "example"
 className: "org.apache.pulsar.functions.api.examples.ExclamationFunction"
 inputs: ["test_src"]
-userConfig:
-  "PublishTopic": "test_result"
-
 output: "test_result"
 autoAck: true
 parallelism: 1
diff --git a/pulsar-functions/java-examples/src/main/resources/example-stateful-function-config.yaml b/pulsar-functions/java-examples/src/main/resources/example-stateful-function-config.yaml
index 605b6b0d..5a6827a 100644
--- a/pulsar-functions/java-examples/src/main/resources/example-stateful-function-config.yaml
+++ b/pulsar-functions/java-examples/src/main/resources/example-stateful-function-config.yaml
@@ -19,12 +19,10 @@
 
 tenant: "test"
 namespace: "test-namespace"
-name: "stateful-example"
+name: "word_count"
 className: "org.apache.pulsar.functions.api.examples.WordCountFunction"
 inputs: ["test_stateful_src"]
-userConfig:
-  "PublishTopic": "test_stateful_result"
-
-output: "test_stateful_result"
+inputs: ["test_wordcount_src"]
+output: "test_wordcount_result"
 autoAck: true
 parallelism: 1
diff --git a/pulsar-functions/java-examples/src/main/resources/example-window-function-config.yaml b/pulsar-functions/java-examples/src/main/resources/example-window-function-config.yaml
index e0faf6f..3edba31 100644
--- a/pulsar-functions/java-examples/src/main/resources/example-window-function-config.yaml
+++ b/pulsar-functions/java-examples/src/main/resources/example-window-function-config.yaml
@@ -22,9 +22,6 @@
 name: "example"
 className: "org.apache.pulsar.functions.api.examples.AddWindowFunction"
 inputs: ["test_src"]
-userConfig:
-  "PublishTopic": "test_result"
-
 output: "test_result"
 autoAck: true
 parallelism: 1