[release] Publish the v0.8 documentation as released version

Author: wuchong

website/community/how-to-release/creating-a-fluss-release.mdx

@@ -768,8 +768,9 @@ Make sure that you are authenticated with your Docker ID, and that your Docker I
 :::
 
 ```bash
-docker tag apache/fluss:${RELEASE_VERSION}_RC${RC_NUM} apache/fluss:${RELEASE_VERSION}
-docker push apache/fluss:${RELEASE_VERSION}
+docker buildx imagetools create apache/fluss:${RELEASE_VERSION}-rc${RC_NUM} --tag apache/fluss:${RELEASE_VERSION}
+
+docker buildx imagetools create apache/fluss-quickstart-flink:1.20-${RELEASE_VERSION}-rc${RC_NUM} --tag apache/fluss-quickstart-flink:1.20-${RELEASE_VERSION}
 ```
 
 ### 6. Update `fluss-versions.json`

website/fluss-versions.json

@@ -10,8 +10,8 @@
     "versionName": "version-0.8",
     "fullVersion": "0.8.0-incubating",
     "shortVersion": "0.8",
-    "dockerVersion": "0.8.0-incubating-rc1",
-    "released": false
+    "dockerVersion": "0.8.0-incubating",
+    "released": true
   },
   {
     "versionName": "version-0.7",