Update dependency yargs to v18

Author: renovate[bot]

package-lock.json

@@ -64,7 +64,7 @@
     "mustache": "^4.0.0",
     "pkg-up": "^3.0.0",
     "popper.js": "^1.16.1",
-    "yargs": "^17.0.0"
+    "yargs": "^18.0.0"
   },
   "devDependencies": {
     "@types/diff2html": "0.0.5",