[#755]improvement(doc): add diqiu50 to maintainer (#770)

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### What changes were proposed in this pull request?

Add diqiu50 to maintainer

### Why are the changes needed?

Fix: #755

### Does this PR introduce _any_ user-facing change?

No
### How was this patch tested?

No

MAINTAINERS.md

@@ -13,4 +13,5 @@ This document lists the maintainers of the Project. Maintainers may be added onc
 | Heng Qin      | qqqttt123           | Datastrato       |
 | McHades       | mchades             | Datastrato       |
 | Xun Liu       | xunliu              | Datastrato       |
+| Hui Yu        | diqiu50             | Datastrato       |
 | Xiaojing Fang | FANNG1              | Datastrato       |