update mixpy index
<script src="../../converters/mixpy_python/turtle.js" type="application/javascript"></script>
<script src="./js/python_to_blockly.js" type="application/javascript"></script>
<script src="js/mixpyProject.js" type="application/javascript"></script>
+ <script src="js/skulpt/dist/skulpt.min.js" type="application/javascript"></script>
+ <script src="js/skulpt/dist/skulpt-stdlib.js" type="application/javascript"></script>
+ <script src="js/skulpt/engine.js" type="application/javascript"></script>
<link rel="stylesheet" type="text/css" href="color_mixpy_python.css" />
<script>
