docs: JS proxy client: explain client keys

website/docs/sdks/proxy-javascript.md

@@ -5,12 +5,14 @@ title: JavaScript Proxy SDK
 
 In this guide we explain how to use feature toggles in a Single Page App via [The Unleash Proxy](/sdks/unleash-proxy). You can also checkout the source code for the [JavaScript Proxy SDK](https://github.com/unleash/unleash-proxy-client-js).
 
-### Introduction {#introduction}
+## Introduction {#introduction}
 
 For single-page apps we have a tiny proxy-client in JavaScript, without any external dependencies, except from browser APIs. This client will store toggles relevant for the current user in local-storage and synchronize with the Unleash Proxy in the background. This means we can bootstrap the toggles for a specific use the next time the user visits the web-page.
 
 > We are looking in to also [supporting react-native](https://github.com/Unleash/unleash/issues/785) with this SDK. Reach out if you want to help us validate the implementation.
 
+## How to use the JavaScript Proxy SDK
+
 **Step 1: Install**
 
 ```
@@ -19,7 +21,7 @@ npm install unleash-proxy-client
 
 **Step 2: Initialize the SDK**
 
-You need to have a Unleash-hosted instance, and the proxy need to be enabled. In addition you will need a proxy-specific clientKey in order to connect to the Unleash-hosted Proxy.
+You need to have an Unleash-hosted instance, and the proxy need to be enabled. In addition you will need a proxy-specific `clientKey` in order to connect to the Unleash-hosted Proxy. For more on how to set up client keys, [consult the Unleash Proxy docs](unleash-proxy.md#configuration-variables).
 
 ```js
 import { UnleashClient } from 'unleash-proxy-client';