Add instructions to build and install it in dev mode

README.md

@@ -25,12 +25,61 @@ commands for quick API testing and integration.
 
 <img alt="screenshot" src="./screenshots/2.png" style="max-width: 100%" />
 
+## Additional configuration on Firefox
+
+Firefox by default doesn't grant `host_permission` for manifest V3 extensions
+[until the upcoming version 127](https://hg.mozilla.org/mozilla-central/rev/a069d7806c9b),
+so in order to enable Twilio Console Plus, head to "Manage Your Extensions" -> "Twilio Console Plus" -> "Permissions" and toggle on the optional permission.
+
+<img src='./screenshots/firefox-permission.png' />
+
 ## Build
 
 ```sh
 npm run build  # Generate the dist/bundle.js
 ```
 
+### Install on Chrome after the build
+
+1. **Open Chrome and Navigate to Extensions Page**
+
+   - Open the Google Chrome browser.
+   - Click on the three vertical dots in the upper-right corner of the browser to open the menu.
+   - Navigate to `More tools` > `Extensions`.
+
+2. **Enable Developer Mode**
+
+   - On the Extensions page, you will see a toggle switch for `Developer mode` in the upper-right corner.
+   - Turn on `Developer mode` by clicking the toggle switch.
+
+3. **Load Unpacked Extension**
+   - Click on the `Load unpacked` button that appears after enabling Developer mode.
+   - A file dialog will open. Navigate to the extension directory `twilio-console-plus`.
+   - Select the folder that contains the extension files and click `Select Folder`.
+
+### Install on Firefox after the build
+
+1. **Open Firefox and Navigate to Add-ons Manager**
+
+   - Open the Mozilla Firefox browser.
+   - Click on the three horizontal lines in the upper-right corner of the browser to open the menu.
+   - Select `Add-ons and themes` from the menu.
+
+2. **Enable Debugging Mode**
+
+   - In the Add-ons Manager, click on the gear icon (⚙️) in the upper-right corner and choose `Debug Add-ons`.
+   - This will open the `about:debugging` page.
+
+3. **Enable Add-on Debugging**
+
+   - On the `about:debugging` page, click on the `This Firefox` tab on the left sidebar.
+   - Enable the `Enable add-on debugging` checkbox.
+
+4. **Load Temporary Add-on**
+   - Click on the `Load Temporary Add-on...` button.
+   - A file dialog will open. Navigate to the extension directory `twilio-console-plus`.
+   - Select the `manifest.json` file in the directory.
+
 ### Package a zip
 
 ```sh