[docs][minor] Add transform piece for pipeline example

This closes  #3496

README.md

@@ -53,19 +53,19 @@ full database synchronization, sharding table synchronization, schema evolution
       password: pass
       
     transform:
-    - source-table: adb.web_order01
-      projection: \*, UPPER(product_name) as product_name
-      filter: id > 10 AND order_id > 100
-      description: project fields and filter
-    - source-table: adb.web_order02
-      projection: \*, UPPER(product_name) as product_name
-      filter: id > 20 AND order_id > 200
-      description: project fields and filter  
+      - source-table: adb.web_order01
+        projection: \*, UPPER(product_name) as product_name
+        filter: id > 10 AND order_id > 100
+        description: project fields and filter
+      - source-table: adb.web_order02
+        projection: \*, UPPER(product_name) as product_name
+        filter: id > 20 AND order_id > 200
+        description: project fields and filter  
 
     route:
-    - source-table: adb.web_order\.*
-      sink-table: adb.ods_web_orders
-      description: sync sharding tables to one destination table
+      - source-table: adb.web_order\.*
+        sink-table: adb.ods_web_orders
+        description: sync sharding tables to one destination table
     
     pipeline:
        name: MySQL to Doris Pipeline

docs/content.zh/docs/core-concept/data-pipeline.md

@@ -79,6 +79,17 @@ We could use following yaml file to define a complicated Data Pipeline describin
      fenodes: 127.0.0.1:8030
      username: root
      password: ""
+  
+   transform:
+     - source-table: adb.web_order01
+       projection: \*, UPPER(product_name) as product_name
+       filter: id > 10 AND order_id > 100
+       description: project fields and filter
+     - source-table: adb.web_order02
+       projection: \*, UPPER(product_name) as product_name
+       filter: id > 20 AND order_id > 200
+       description: project fields and filter
+
    route:
      - source-table: app_db.orders
        sink-table: ods_db.ods_orders

docs/content/docs/core-concept/data-pipeline.md

@@ -57,6 +57,24 @@ We could use following yaml file to define a concise Data Pipeline describing sy
      username: root
      password: ""
 
+   transform:
+     - source-table: adb.web_order01
+       projection: \*, UPPER(product_name) as product_name
+       filter: id > 10 AND order_id > 100
+       description: project fields and filter
+     - source-table: adb.web_order02
+       projection: \*, UPPER(product_name) as product_name
+       filter: id > 20 AND order_id > 200
+       description: project fields and filter
+
+   route:
+     - source-table: app_db.orders
+       sink-table: ods_db.ods_orders
+     - source-table: app_db.shipments
+       sink-table: ods_db.ods_shipments
+     - source-table: app_db.products
+       sink-table: ods_db.ods_products
+
    pipeline:
      name: Sync MySQL Database to Doris
      parallelism: 2