chore: add CODEOWNERS for /doc

Author: necusjz

.github/CODEOWNERS

@@ -6,7 +6,7 @@
 
 /linter_exclusions.yml @jsntcy @kairu-ms @zhoxing-ms
 
-/doc/ @jiasli @kairu-ms @jsntcy
+/doc/ @jiasli @kairu-ms @jsntcy @necusjz @yanzhudd
 /tools/ @kairu-ms @jiasli @wangzelin007 @calvinhzy @bebound
 /tools/aaz-flow @a0x1ab @necusjz @yanzhudd
 /scripts/ @kairu-ms @jiasli @wangzelin007 @calvinhzy @bebound