Added description and usage to readme

README.md

@@ -1,2 +1,33 @@
-# PyStudio
+# PyCanvas
 
+PyCanvas is a Skulpt library for creating 2D games. It is based on litecanvas, and uses the HTML Canvas API. The demo editor is available at [PyStudio](https://pystudio.haaxman.co.uk/) and provides a nice online editor for writing code.
+
+## Usage
+
+To use PyCanvas, you can add the following to the top of your skulpt builtInRead() function:
+
+```javascript
+if (x === 'screen' || x === './screen.js') {
+    const xhr = new XMLHttpRequest();
+    xhr.open("GET", "path/to/screen.js", false);
+    xhr.send();
+    if (xhr.status === 200) return xhr.responseText;
+    else throw "Could not load screen.js";
+}
+```
+
+Then you can use it in your code like this:
+
+```python
+import screen as s
+
+def draw():
+    s.cls(0)
+    s.text(20, 20, "Hello World!", 3)
+
+s.start({
+    "loop":{
+        "draw":draw
+    }
+})
+```