Update README.md

- Add the Chrome Web Store link to the installation section.
- Add a usage section to explain how to use the extension.

Author: canova

README.md

@@ -9,13 +9,30 @@ both browsers.
 
 ## How to install
 
+[The Firefox Profiler extension can be installed from the Chrome Web Store.](https://chromewebstore.google.com/detail/firefox-profiler/ljmahpnflmbkgaipnfbpgjipcnahlghn)
+
+### Manual install
+
+If you would like to install the extension directly from its source code, you
+can follow the steps below:
+
 - Clone the repository.
 - Navigate to `chrome://extensions/` and enable the developer mode on the top
   right corner.
 - Click "Load unpacked" and select the extension folder.
 - Once loaded, the extension icon should appear inside the "Extension" menu on
   your Chrome toolbar. Click on the "Pin" button to add it to the toolbar directly.
 
+## Usage
+
+Using the extension is straightforward:
+
+1. Once you've installed the extension and added it to your toolbar, simply click the Firefox Profiler button to begin recording. Alternatively, you can start recording by pressing `Ctrl+Shift+1`.
+
+2. Now that the profiler is recording, perform the actions you'd like to capture.
+
+3. When you've completed the actions, click the Firefox Profiler button again to stop recording and capture the profile. You can also press `Ctrl+Shift+2` to finalize the profile and open it in Firefox Profiler.
+
 ## Development
 
 Currently there is no bundler in the project for faster development. But we do