Added demo class

Demo.pde

@@ -0,0 +1,26 @@
+class Demo{
+  PVector pos;
+  
+  Demo(PVector _pos){
+    pos = _pos.copy();
+  }
+  Demo(float x, float y){
+    this(new PVector(x,y));
+  }
+  
+  void display(){ // Move and then draw a circle when display is called
+    move();
+    noStroke();
+    fill(100);
+    circle(pos.x,pos.y,10);
+  }
+  
+  // Check if each key is in the keys array. 
+  // Notice I do not use else if, because I want multiple to be able to trigger at once.
+  private void move(){ 
+    if(findInt(keys,'w') != -1){ pos.y -= 2; }
+    if(findInt(keys,'a') != -1){ pos.x -= 2; }
+    if(findInt(keys,'s') != -1){ pos.y += 2; }
+    if(findInt(keys,'d') != -1){ pos.x += 2; }
+  }
+}