Update README.md

+ intro, installation, usage

README.md

@@ -1 +1,11 @@
-# gm-jira-copy
+# About
+
+This project contains various handy user scripts for the Greasemonkey (in Firefox; GM) and Tampermonkey (in Chrome; TM) browser addons.
+
+# Installation
+
+Firstly install the aforementioned addon for your favorite browser and then simply open the selected *\*.user.js* file in the browser. GM (or TM) will guide you through the rest of the user script installation. The most important thing to do is to set up the pages for which you want to have the given user script activated. You can always find an example of the appropriate "include pattern" right in the installed user script.
+
+# Usage
+
+The usage is always specific to a given user script. Most user scripts should offer a special help dialog that can be opened via the GM / TM tollbar icon. And of course, you can always look into the script's source code and see what it actually does... :)