added folder

src/main/webapp/com/ardublock/reference/404.html

src/main/webapp/com/ardublock/reference/loop.html

src/main/webapp/com/ardublock/reference/loop.jpg

src/main/webapp/com/ardublock/reference/loop.png

src/main/webapp/com/ardublock/reference/program_comment.html

src/main/webapp/com/ardublock/reference/program_comment.png