Defined supported node versions in engines field (#113)

Author: AhmarZaidi

package.json

@@ -2,6 +2,9 @@
   "name": "ag-viewer",
   "version": "0.0.1",
   "private": true,
+  "engines": {
+    "node": "^14.16.0"
+  },
   "scripts": {
     "setup": "npm install && npm-run-all setup-front setup-backend",
     "setup-front": "cd frontend && npm install",