[Feature][doc] Repair md document format (#9177)

Author: CosmosNi

Diff for: docs/en/connector-v2/source/GraphQL.md

@@ -116,7 +116,7 @@ Source plugin common parameters, please refer to [Source Common Options](../sour
 
 ## Example
 
-### Query:
+### Query
 
 ```hocon
 source {

Diff for: docs/zh/connector-v2/source/GraphQL.md

@@ -116,7 +116,7 @@ HTTP请求参数
 
 ## 示例
 
-### Query:
+### Query
 
 ```hocon
 source {