Progress bar

Very basic progress bar. The Javascript updates the text of two elements: the progress bar that counts by 1 and the message that counts by 10. The last one has an aria-live="polite" attribute/value that will make changes to it available to the accessibility API.

Announcing the changes to the progress bar proper (counting by 1) was not feasable as the screen reader (VoiceOver and NVDA) could not keep up.