rename coffeescript to coffee.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
convert 4 spaces to 2 spaces

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
fixed fork link

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
update 404 page.

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>
ref: https://github.com/h5bp/html5-boilerplate/issues/1542

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>