first commit

src/main.js

+// 1. initialize
+console.log("program starting");
+const router = require("./router");
+const PORT = 3000;
+const HOST = "127.0.0.1"; // 0.0.0.0
+// 2. operate
+router.listen(
+    PORT, 
+    HOST,
+    () => console.log(`Listening to http://${HOST}:${PORT}`)
+); // backticks
+// 3. cleanup
+console.log("program ending");