Quickstart example app.js code throws errors via koa-router

[mberkowski]

The current README Quickstart app.js code

'use strict';
const janus = require('./');
const pubmedPlugin = require('./test/fixtures/pubmed-plugin');
const app = janus({
  uriFactoryPlugins: {pubmed: pubmedPlugin},
});
app.listen(3000);

Does not execute under Node 16 (at least). Koa-router seems to be expecting a string somewhere and getting instead an undefined from the barebones way the example is setup.

/src/src/janus/janus/node_modules/koa-router/node_modules/path-to-regexp/index.js:89
  if (index < str.length) {
                  ^

TypeError: Cannot read properties of undefined (reading 'length')
    at parse (/src/src/janus/janus/node_modules/koa-router/node_modules/path-to-regexp/index.js:89:19)
    at stringToRegexp (/src/src/janus/janus/node_modules/koa-router/node_modules/path-to-regexp/index.js:319:16)
    at pathToRegexp (/src/src/janus/janus/node_modules/koa-router/node_modules/path-to-regexp/index.js:425:10)
    at new Layer (/src/src/janus/janus/node_modules/koa-router/lib/layer.js:47:17)
    at Router.register (/src/src/janus/janus/node_modules/koa-router/lib/router.js:553:15)
    at Router.<computed> [as get] (/src/src/janus/janus/node_modules/koa-router/lib/router.js:202:10)
    at Object.<anonymous> (/src/src/janus/janus/index.js:69:12)
    at r (/src/src/janus/janus/node_modules/stampit/dist/stampit.min.js:1:1596)
    at Object.<anonymous> (/src/src/janus/janus/app.js:4:13)