Update README.md

Author: pfvatterott

README.md

@@ -1,6 +1,6 @@
 <p align="center">
   <a href="https://www.propelauth.com?ref=github" target="_blank" align="center">
-    <img src="https://propelauth-logos.s3.us-west-2.amazonaws.com/logo-only.png" width="100">
+    <img src="https://www.propelauth.com/imgs/lockup.svg" width="200">
   </a>
 </p>
 
@@ -17,6 +17,60 @@ Your frontend gets a beautiful, safe, and customizable login screen. Your backen
 - Full reference this library is [here](https://docs.propelauth.com/reference/frontend-apis/js)
 - Getting started guides for PropelAuth are [here](https://docs.propelauth.com/)
 
+## Installation and Usage
+
+```bash
+npm install @propelauth/javascript
+```
+
+and then you can import it:
+
+```js
+import { createClient } from "@propelauth/javascript";
+```
+
+Alternatively, you can use a CDN:
+
+```html
+<script 
+    src="https://www.unpkg.com/@propelauth/javascript@2.0.11/dist/javascript.min.js" 
+    integrity="sha384-FENNH2f7QuQvkZJBL7jebLr0OtYKgTA2iq+C5g3VXXX7SBwWmeMMoc+pBBtcn76G" 
+    crossorigin="anonymous"></script>
+```
+
+then a global PropelAuth object will be created, and you can call createClient from it:
+
+```html
+<script>
+  PropelAuth.createClient({...});
+</script>
+```
+
+## Using the Javascript library
+
+You'll create a client using the [createClient](#create-client) function, and then you can use the client to get information about the current user.
+
+You can also enabled background token refresh, which will automatically refresh the user's information periodically and on key events (e.g. user switches tabs, reconnects to the internet, etc).
+
+
+### createClient
+
+Creates an authentication client which manages your user's [access token](https://docs.propelauth.com/guides-and-examples/guides/access-tokens), fetches user information, and provides other useful authentication functions.
+
+The client also refreshes auth information when a user switches focus to your tab or reconnects (if they were offline).
+
+```js
+const authClient = createClient({
+  // The base URL where your authentication pages are hosted.
+  // You can find this under the Frontend Integration section for your project.
+  authUrl: "https://auth.yourdomain.com",
+
+  // If true, periodically refresh the access token in the background.
+  // This helps ensure you always have a valid token ready to go. Default true.
+  enableBackgroundTokenRefresh: true,
+});
+```
+
 ## Questions?
 
 Feel free to reach out at support@propelauth.com