lint: apply standard 15 style

Author: dougwilson

package.json

@@ -18,7 +18,7 @@
   "devDependencies": {
     "bluebird": "3.7.2",
     "eslint": "8.17.0",
-    "eslint-config-standard": "14.1.1",
+    "eslint-config-standard": "15.0.1",
     "eslint-plugin-import": "2.26.0",
     "eslint-plugin-markdown": "2.2.1",
     "eslint-plugin-node": "11.1.0",