Added signed xpi for firefox users.

README.md

@@ -19,12 +19,10 @@ Just another minimal startpage for browsers.
 - On chrome, open extensions from the tool menu or open it from [chrome://extensions](chrome://extensions).
 - Click on load unpacked, navigate to the directory where you cloned the repo and select it.
 
-### Firefox (temporary)
+### Firefox
 
-- Open ```about:debugging``` from your Firefox browser.
-- Click on This Firefox and select ```Load Temporary Add On...```
-- Open the cloned repo directory and select any file there (preferrably ```manifest.json```)
-- It should be installed.
+- Get the latest ```xpi``` file from the dist directory.
+- Go to add ons from Firefox and select the xpi file you downloaded, it should be installed.
 
 ## Upcoming