docs: better local development instructions

README.md

@@ -34,21 +34,41 @@ The folder for audio files can be found at `audio/`.
     the National Rail Journey Planner.
   - _For example, Brighton should be `BTN.mp3`._
 
-### Website contributions
+### Running the website locally
 
-This site is created with the React Framework using Gatsby. If you're not familiar with React or Gatsby, you may want to research them before
-contributing.
+You'll need to install [Node.js](https://nodejs.org/en) and the [Yarn package manager](https://yarnpkg.com/getting-started/install) as
+prerequisites.
 
-**Set up dev environment:**
+When you've cloned the repository, install the required dependencies with Yarn:
 
-```
-git clone https://github.com/davwheat/rail-announcements
+```bash
 yarn install
-yarn start
 ```
 
-**Before committing your changes, format your code:**
+Then you can start the three (yes, three) development services:
+
+```bash
+# In one terminal, run (for the website):
+yarn run develop
 
+# When this says "You can now view rail-announcements in the browser.", open a new terminal and run (for the live trains API):
+yarn run develop:workers
+
+# Finally, open a new terminal and run (to serve the audio files):
+yarn run serve-audio
 ```
+
+You'll be able to access the website at [http://local.davw.network:8787](http://local.davw.network:8787). `local.davw.network` is a domain that
+will always resolve to your local machine, and is used to ensure that the website works correctly with the audio files and backend API during
+local development.
+
+### Website contributions
+
+This site is created with the React Framework using Gatsby. If you're not familiar with React or Gatsby, you may want to research them before
+contributing.
+
+**Before committing your changes, format your code:**
+
+```bash
 yarn run format
 ```

package.json

@@ -13,7 +13,7 @@
   ],
   "scripts": {
     "develop": "gatsby develop",
-    "develop:workers": "wrangler pages dev --proxy 8000",
+    "develop:workers": "wrangler pages dev --proxy 8000 --port 8087",
     "start": "gatsby develop",
     "build": "gatsby build",
     "build:ci": "cross-env NODE_ENV=production gatsby build --verbose && (yarn run sentry:sourcemaps || true)",