Add sound effects for lab successes

[david-a-wheeler]

Add some small sound effects when there is a lab success. The goal is to be (1) motivating, and (2) aid accessibility for those who cannot perceive the background color changes that we perform to indicate partial success.

[david-a-wheeler]

I have intentionally not merged this PR yet. I think it would help by providing additional feedback, but some might not like it.

PLEASE provide feedback if you would like this added (+1) or would NOT like this added (-1).

[ctcpip]

technically, the longer sound does not meet WCAG 1.4.2, but the issue is minor and probably fine

aid accessibility for those who cannot perceive the background color changes that we perform to indicate partial success

per WCAG 1.4.1, can some other visual indicator be added for this?

[david-a-wheeler]

The problem is space. I could add an icon (like "thumbs-up" or "check") to its right, but since people are typing in code, space is already at a premium (ESPECIALLY on mobile).

I could add a temporary pop-up on partial solutions. That's not perfect either, obviously.

Maybe this just isn't worth it.

[david-a-wheeler]

I've gotten a lot of "please don't", so I'll quietly close this :-).