Updated Development Quickstart (markdown)

Development-Quickstart.md

@@ -54,7 +54,7 @@ _Note:_ The dev script will abort if the web UI index.html file is not found.
 
 This will launch Inbucket with a development friendly configuration with debug logging and storing mail in /tmp/inbucket.  The retention period is reduced to 3 hours to encourage you to send in fresh mail periodically.
 
-Point your web browser at http://127.0.0.1:9000/ then select the Monitor tab.
+Point your web browser at http://0.0.0.0:9000/ then select the Monitor tab.
 
 ## Terminal 2
 
@@ -67,3 +67,20 @@ etc/swaks-tests/run-tests.sh
 You should see the emails listed in your web browser, as well as a bunch of Inbucket debug logging in Terminal 1.
 
 After you make changes to the backend, kill the inbucket process and repeat the steps above to test it.
+
+# Frontend development
+
+Frontend development still requires a running backend, so follow the _Terminal 1_ steps in the Backend section before proceeding.
+
+## Terminal 3
+
+Build & launch the frontend in development mode:
+
+```sh
+cd ui
+npm run dev
+```
+
+If your browser does not open automatically, visit http://0.0.0.0:3000/ and select the Monitor tab.  Follow the steps for _Terminal 2_ in the backend section to send some messages into Inbucket and confirm they appear in your browser.
+
+The development server features hot code loading, so most changes you make to the Elm code will not require a reload.