made readme useful

README.md

@@ -2,4 +2,32 @@
 
 A little tool to make element manipulation sensitive to scrolling easier. It was originally made for my [portfolio project](https://github.com/slri/yet-another-portfolio) since no other tool had what I needed or included a lot of other functionality which I didn't need. jQuery is required for it to work, but I want to improve it further and get rid of the jQuery dependency.
 
-Implemented some of the best practices for creating front end tools, but there's a lot of room for improvement.
+## How to use
+
+It takes opts object which can look like this (they're all optional):
+
+Property | Type | Description | Default | Example
+--- | --- | --- | --- | ---
+animation | integer | animation duration in ms | 500 | 500
+viewport | integer | being the visible area (viewport) of the page, where 0 is vertical topmost point, 50 is the middle, and 100 is the bottom | 50 | 50
+target | query string | element which will be affected by the changes based on scroll progress | "#target" | "#target"
+trigger | query string | element who's start and (by default) total height will determine the trigger area | "#trigger" | "#trigger"
+duration | integer | where the trigger area will end in pixels | trigger.outerHeight() | 400
+
+The callback function will get step/progress from 0 to 100 of how far the viewport point specified has gotten from the beginning to the end of the trigger and the target element itself as arguments. Example:
+
+```js
+scrollicious({trigger: "#contact", viewport: 90}, function(step, target) {
+
+	var color = originalColor.toHsv();
+
+	color.v += (transitionColor.v - color.v) * (step/100);
+
+	target.css("color", tinycolor(color).toHexString());
+});
+```
+
+
+If you'd prefer looking at the code itself, scrollicious is commented every step of the way.
+
+There's a lot of room for improvement.