Update README.md

Update README, add instructions for hosting deploy to emulator.

Author: jenh

Node/call-vertex-remote-config-server/README.md

@@ -4,11 +4,13 @@ Call the Vertex AI Gemini API with Remote Config and App Check
 Introduction
 ------------
 
-This is a sample callable function that authenticates calling apps with App
+This is a sample callable function that authenticates clients with App
 Check and then sends queries to Gemini using the Vertex AI Gemini API. Vertex
-AI model parameters are controlled using the Remote Config server
-functionality provided by the Firebase Admin SDK for Node.js. Use the client
-provided in `client/` to access the function through basic web page.
+AI model parameters (including the model itself) are controlled by
+Remote Config server features included in the Firebase Admin SDK for
+Node.js.
+
+Use the web client provided in `client/` to test the function.
 
 - [Read more about Remote Config for servers](https://firebase.google.com/docs/remote-config/server).
 - [Read more about App Check](https://firebase.google.com/docs/app-check).
@@ -26,22 +28,44 @@ Get Started
 ---------------
 
  1. Follow the instructions in client/README.md to create a Firebase project,
-    enable ReCAPTCHA Enterprise, enable Firebase App Check, and add your
-    Firebase config and ReCAPTCHA Enterprise key to the client config.
+    enable ReCAPTCHA Enterprise, enable and enforce Firebase App Check, and add
+    your Firebase config and ReCAPTCHA Enterprise key to the client config.
+ 
  2. Enable [recommended Vertex AI APIs](https://console.cloud.google.com/vertex-ai).
+ 
  3. Configure a Remote Config server template on the Firebase console. Use the template
     described in
     [Use server side Remote Config with Cloud Functions and Vertex
     AI](https://firebase.google.com/docs/remote-config/solution-server#implementation-create-template),
-    which contains all of the parameters used in the function sample.
+    which contains all of the parameters used in this function sample.
+ 
  4. Install dependencies: `cd functions && npm install`
- 5. If you haven't already done so, install firebase-tools: `npm i firebase-tools@latest`
- 6. Log into Firebase: `firebase login`
+ 
+ 5. If you haven't already done so, install firebase-tools:
+  
+    `npm i firebase-tools@latest`
+ 
+ 6. Log into Firebase:
+ 
+    `firebase login`
+ 
  7. Deploy the function. We recommend testing in the
-    [Firebase emulator](https://firebase.google.com/docs/remote-config/solution-server#implementation-deploy-and-test-in-emulator).
+    [Firebase emulator](https://firebase.google.com/docs/remote-config/solution-server#implementation-deploy-and-test-in-emulator):
+ 
+    `firebase emulators:start`
+ 
  8. If testing in the emulator, verify that `testMode` is set to `true` in
-   `client/main.ts`, then start the client: `cd public && npm run dev`
- 9. Open the [client app in a browser](http://localhost:5173) and enter a
+     `client/main.ts`, then start the client:
+
+    `cd client && npm run dev`
+
+    TIP: If you're using the emulator, you can deploy both the function and hosting
+         to the emulator. From the `client` directory, run `npm run build`.
+         Then, from the parent directory, run `firebase server --only functions,hosting`.
+         Open http://localhost:5000 to access and test the web client's connection
+         to the `callVertexWithRC` function.
+    
+ 0. Open the [client app in a browser](http://localhost:5173) and enter a
     prompt. To access the Vertex AI Gemini API, make sure that you have
     set the `is_vertex_enabled` boolean parameter in your Remote Config
     server template to `true`.