Fix broken links (#2350)

Author: gaearon

packages/react-scripts/template/README.md

@@ -1403,7 +1403,7 @@ If your production web server does not support HTTPS, then the service worker
 registration will fail, but the rest of your web app will remain functional.
 
 1. Service workers are [not currently supported](https://jakearchibald.github.io/isserviceworkerready/)
-in all web browsers. Service worker registration [won't be attempted](src/service-worker-registration.js)
+in all web browsers. Service worker registration [won't be attempted](src/registerServiceWorker.js)
 on browsers that lack support.
 
 1. The service worker is only enabled in the [production environment](#deployment),
@@ -1419,7 +1419,7 @@ instructions for one way to test your production build locally and the [deployme
 instructions for using other methods. *Be sure to always use an
 incognito window to avoid complications with your browser cache.*
 
-1. If possible,configure your production environment to serve the generated
+1. If possible, configure your production environment to serve the generated
 `service-worker.js` [with HTTP caching disabled](http://stackoverflow.com/questions/38843970/service-worker-javascript-update-frequency-every-24-hours).
 If that's not possible—[GitHub Pages](#github-pages), for instance, does not
 allow you to change the default 10 minute HTTP cache lifetime—then be aware
@@ -1437,7 +1437,7 @@ app works offline!" message) and also let them know when the service worker has
 fetched the latest updates that will be available the next time they load the
 page (showing a "New content is available; please refresh." message). Showing
 this messages is currently left as an exercise to the developer, but as a
-starting point, you can make use of the logic included in [`src/service-worker-registration.js`](src/service-worker-registration.js), which
+starting point, you can make use of the logic included in [`src/registerServiceWorker.js`](src/registerServiceWorker.js), which
 demonstrates which service worker lifecycle events to listen for to detect each
 scenario, and which as a default, just logs appropriate messages to the
 JavaScript console.