USWDS - Character count: Create an MVP for an audible cue when the character limit is exceeded

[amyleadem]

Summary

Implement an audible cue, such as a ding, when the character limit is exceeded. It should only ding one time once the first character over the limit is typed, not ding every time they type over the limit. Pair this audible cue with the message "you are x characters over the limit" for screen readers.

Details

We should explore the options for immediate audible cues when the character count max is reached. This should work alongside the current "polite" message that explains how many characters over the limit they are. Possible options are a short phrase like "over limit" or a distinct and easy-to-understand sound effect.