chore: Add @keydunov as CODEOWNERS for docs-mintlify (cube-js#10831)

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: keydunov

CODEOWNERS

@@ -25,7 +25,8 @@
 /packages/*-schema-extension/          @cube-js/schema-compiler
 
 # Doc reviewers
-/docs/      @cube-js/doc-reviewers
+/docs/           @cube-js/doc-reviewers
+/docs-mintlify/  @keydunov
 
 # Developer Relations and Community
 /examples/  @cube-js/developer-relations-and-community