docs(protobuf): change transaction data structure description (#5602)

Co-authored-by: liukai <kayle.liu@tron.network>

Author: forfreeday

Tron protobuf protocol document.md

@@ -546,11 +546,11 @@ Transaction and transaction-related messages.
 
   message `raw`
 
-   `ref_block_bytes`: Deprecated.
+   `ref_block_bytes`: intercepted part of the now block bytes in transaction head.
 
-   `ref_block_num`: now block number in transaction head.
+   `ref_block_num`: Deprecated.
 
-   `ref_block_hash`: now block hash in transaction head.
+   `ref_block_hash`:intercepted part of the now block hash in transaction head..
 
    `expiration`: the expiration time in transaction head.
 
@@ -565,15 +565,15 @@ Transaction and transaction-related messages.
    ```java
   message raw {
       bytes ref_block_bytes = 1;
-    int64 ref_block_num = 3;
+      int64 ref_block_num = 3;
       bytes ref_block_hash = 4;
-    int64 expiration = 8;
+      int64 expiration = 8;
       repeated authority auths = 9;
-    bytes data = 10;
+      bytes data = 10;
       repeated Contract contract = 11;
-    bytes scripts = 12;
+      bytes scripts = 12;
       int64 timestamp = 14;
-    int64 fee_limit = 18;
+      int64 fee_limit = 18;
     }
    ```