Add rudimentary command line parsing to express app

express/app.ts

@@ -3,6 +3,7 @@ import express, {
     Response as ExpressResponse,
 } from "express";
 import { match } from "path-to-regexp";
+import { cli } from "./cli";
 import { contentTypes } from "./content-types";
 import { httpCodes } from "./http-codes";
 import { routes } from "./routes";
@@ -117,4 +118,6 @@ app.use(async (req: ExpressRequest, res: ExpressResponse) => {
     res.status(code).send(result);
 });
 
-app.listen(3000);
+app.listen(cli.listen.port, cli.listen.host, () => {
+    console.log(`Listening on ${cli.listen.host}:${cli.listen.port}`);
+});