Update README.md

Author: tim-we

README.md

@@ -1,4 +1,11 @@
 # Tabs Aside!
-a simple WebExtension providing something similar to the Microsoft Edge feature Tabs Aside
+a simple and easy-to-use tab manager for Firefox, inspired by the Microsoft Edge feature Tabs Aside.
 
 [![addons.mozilla.org/](https://addons.cdn.mozilla.net/static/img/addons-buttons/AMO-button_2.png)](https://addons.mozilla.org/firefox/addon/tabs-aside)
+
+# Run the source code
+
+Go to `about:debugging` and click `Load temporary Add-on` and select `manifest.json` (located in the tabs aside root directory).
+It is recommended not to use your main profile as development vesions might corrupt data. To create a new profile go to `about:profiles`.
+
+If you have [web-ext](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Getting_started_with_web-ext) installed simply run `web-ext run` inside the tabs aside root directory.