Merge pull request #48864 from b1gb4by/add/add-reviewer-b1gb4by

[ja] Add b1gb4by to sig-docs-ja reviewer

Author: k8s-ci-robot

OWNERS_ALIASES

@@ -133,6 +133,7 @@ aliases:
     - Okabe-Junya
   sig-docs-ja-reviews: # PR reviews for Japanese content
     - atoato88
+    - b1gb4by
     - bells17
     - inductor
     - kakts