add more commands to reference section

README.md

@@ -31,7 +31,11 @@ penup(); //will draw a line with movement commands
 
 pendown(); //will move to x,y coordinates without drawing line
            //By default, pendown is on / true
-
+penColor('colorName'); //any color word: purple, grey, blue, etc.
+		       //color name must be in single or double quotes!
+                       //or a HTML color like #ff4d4d (in quotes!)
+penSize(n);	       //width of pen in pixels
+		       
 //randomness
 
 randint(n); //returns a random int between 0 and n (exclusive)