Upgrade to React 18 latest LTS

- Installed node 20.10.0 LTS
 - Installed React 18.3.1 (April 2024)
 - resolved vulnerabilities from recommendations [here](facebook/create-react-app#13564 (comment))
 - installed cross-env package.  This will allow the `GENERATE_SOURCEMAP environment` variable to be set on build for all environments.  `GENERATE_SOURCEMAP=false` will not create the ts (TypeScript) map files at runtime
 - resolved 1 linting warning in `links.js`

.eslintrc

@@ -1,13 +1,22 @@
 {
   "extends": [
     "react-app",
-    "airbnb",
     "plugin:jsx-a11y/recommended",
     "plugin:react/jsx-runtime",
+    "prettier",
+  ],
+  "plugins": [
+    "jsx-a11y", 
     "prettier"
   ],
-  "plugins": ["jsx-a11y", "prettier"],
   "rules": {
-    "react/jsx-filename-extension": [1, { "extensions": [".js", ".jsx"] }]
+    "react/jsx-filename-extension": [
+      1, 
+      { 
+        "extensions": [
+          ".js", 
+          ".jsx"
+        ] 
+      }]
   }
 }