Update README.md

Author: Sascha L

README.md

@@ -1,2 +1,16 @@
 # pwgen
 A simple and short javascript-based password generator
+
+## features
+- choose length of password (min 6)
+- include a personal string (e.g. your name, birth date, ...)
+- copy to clipboard
+- debug information
+
+## usage
+```html
+<script>
+  $('.your-class').pwgen();
+</script>
+```
+