Update to node 18.x (actions#751)

Author: feelepxyz

README.md

@@ -86,7 +86,7 @@ steps:
 - uses: actions/checkout@v3
 - uses: actions/setup-node@v3
   with:
-    node-version: 16
+    node-version: 18
 - run: npm ci
 - run: npm test
 ```