Add Netlify build config (command, publish dir, Node 20)

Author: AlexBeesley

netlify.toml

@@ -1,3 +1,10 @@
+[build]
+    command = "npm run build"
+    publish = "build"
+
+[build.environment]
+    NODE_VERSION = "20"
+
 [[redirects]]
     from = "/*"
     to = "/index.html"