typo link

Author: lukegalbraithrussell

docs/english/_sidebar.json

@@ -75,7 +75,7 @@
 		"label": "日本語 (日本)",
 		"link": {
 			"type": "doc",
-			"id": "java-slack-sdk/ja-jp/guides/index"
+			"id": "java-slack-sdk/ja-jp/index"
 		},
 		"items": [
 			"java-slack-sdk/ja-jp/index",