Add AMO link to addon

Author: mbad0la

README.md

@@ -2,7 +2,8 @@
 A firefox addon facilitating client to stay connected to his account without logging into the github website.
 
 #####Installation
-The addon isn't yet listed on Mozilla's Addon website, however you can still install it simply by using [GitHub Extension Installer](https://addons.mozilla.org/en-US/firefox/addon/github-extension-installer/) addon, or by installing it [manually](https://accessfirefox.org/Install_Addon_Manually.php).
+Install the addon for:
+* [Firefox](https://addons.mozilla.org/addon/minigithub/)
 
 
 #####About the addon