change readme for 0.3.0 release (#459)

### What problem does this PR solve?


### Type of change

- [x] Documentation Update

docker/.env

@@ -25,6 +25,8 @@ MINIO_PASSWORD=infini_rag_flow
 
 SVR_HTTP_PORT=9380
 
+RAGFLOW_VERSION=v0.3.0
+
 TIMEZONE='Asia/Shanghai'
 
 ######## OS setup for ES ###########

docker/docker-compose-CN.yml

@@ -9,7 +9,7 @@ services:
         condition: service_healthy
       es01:
         condition: service_healthy
-    image: swr.cn-north-4.myhuaweicloud.com/infiniflow/ragflow:v0.2.0
+    image: swr.cn-north-4.myhuaweicloud.com/infiniflow/ragflow:${RAGFLOW_VERSION}
     container_name: ragflow-server
     ports:
       - ${SVR_HTTP_PORT}:9380

docker/docker-compose.yml

@@ -9,9 +9,10 @@ services:
         condition: service_healthy
       es01:
         condition: service_healthy
-    image: infiniflow/ragflow:v0.2.0
+    image: infiniflow/ragflow:${RAGFLOW_VERSION}
     container_name: ragflow-server
     ports:
+      - ${SVR_HTTP_PORT}:9380
       - ${SVR_HTTP_PORT}:9380
       - 80:80
       - 443:443