Move redirections into redirect-folder

Author: Saisang

.openpublishing.publish.config.json

@@ -124,6 +124,7 @@
     "name": "docfx_v3"
   },
   "redirection_files": [
-    "redirections/.openpublishing.redirection.simplify-package-structure.json"
+    "redirections/.openpublishing.redirection.simplify-package-structure.json",
+	"redirections/.openpublishing.redirection.legacy.json"
   ]
 }