Reworded descriptions for development versions and latest version (#3132)

### What problem does this PR solve?



### Type of change


- [x] Documentation Update

docs/guides/upgrade_ragflow.md

@@ -7,12 +7,10 @@ slug: /upgrade_ragflow
 
 You can upgrade RAGFlow to dev version or the latest version:
 
-- Dev versions are for developers and contributors. They are published on a nightly basis and may crash because they are not fully tested. We cannot guarantee their validity and you are at your own risk trying out latest, untested features.
-- The latest version refers to the most recent, officially published release. It is stable and works best with regular users.
+- A Dev version (Development version) is the latest, tested image.
+- The latest version is the most recent, officially published release.
 
-To upgrade RAGFlow to the dev version:
-
-Update the RAGFlow image and restart RAGFlow:
+## Upgrade RAGFlow to the dev version
 
 1. Update **ragflow/docker/.env** as follows:
 
@@ -27,7 +25,7 @@ Update the RAGFlow image and restart RAGFlow:
    docker compose -f docker/docker-compose.yml up -d
    ```
 
-To upgrade RAGFlow to the latest version:
+## Upgrade RAGFlow to the latest version
 
 1. Update **ragflow/docker/.env** as follows: