create separate md file for interactive materials

These should be all the interactive tutorials from the main md file that we discussed earlier today.   

Some are pretty obvious that they are interactive, but there are about two that are less obvious.  The "Go By Example" is included there because it provides "Go Playground" where you can edit the code.   The second one is "HTML Canvas Deep Dive, but I'm also including it since it does have some pages you can interact with (for example: http://joshondesign.com/p/books/canvasdeepdive/chapter01.html#simple_drawing).   Feel free to remove them or I can make the modification if needed.