🤖 config(xo): Add doc env override.

These changes were automatically generated by a transform whose code can be found at:
  - https://github.com/make-github-pseudonymous-again/rejuvenate/blob/8134808bd3e9bcbb3e4b2ca5401e2dee58965a01/src/transforms/xo:config-add-doc-env-override.js
Please contact the author of the transform if you believe there was an error.

package.json

@@ -214,6 +214,14 @@
       "lib",
       "doc",
       "test/_old"
+    ],
+    "overrides": [
+      {
+        "files": [
+          "doc/**"
+        ],
+        "env": "browser"
+      }
     ]
   }
 }