Issue on docs distribute-hint

- Page Link: https://doris.apache.org/zh-CN/docs/query-acceleration/hints/distribute-hint#%E6%A1%88%E4%BE%8B

- Version: 2.1

- Reason: Hint Used is missing the broadcast hint.（Hint Used 缺少了广播的hint)

- Suggest:正确内容如下（我已经在本地的2.1.6环境验证）

```sql
Planner: Nereids Planner
--
PhysicalResultSink
--hashAgg[GLOBAL]
----PhysicalDistribute[DistributionSpecGather]
------hashAgg[LOCAL]
--------PhysicalProject
----------hashJoin[INNER_JOIN] hashCondition=((t1.c1 = t2.c2)) otherCondition=()
------------PhysicalProject
--------------PhysicalOlapScan[t2]
------------PhysicalDistribute[DistributionSpecReplicated]
--------------PhysicalProject
----------------PhysicalOlapScan[t1]
 
Hint log:
Used: [broadcast]_2 ORDERED
UnUsed:
SyntaxError:
```

- May I contribute to this pull request? Our company has been frequently using Doris lately. If given the chance, I would also like to gradually become involved in the community.（如果确认该Issue的话，可以由我来提交PR吗，我很希望参与到doris社区当中）

- ScreenShot: