Draft updated icons guidance based on literature review findings

[jaclinec]

This work is an extension of what came out of the recently completed icons literature review. We're updating our icons guidance to clarify and emphasize:

• when icons should and shouldn't be preceivable to screen readers
• emphasize that icons should serve as recognizable symbols/pictograms that serve a functional purpose, distinguished from illustrations.
• explain that universally recognized icons are rare and emphasize the importance of testing icon recognition and memorability with your users if you suspect an icon is ambiguous.

[jaclinec]

The draft of the updated icons guidance suggestions is a work in progress.

[jaclinec]

Now that I've had a chance to present the lit review findings to the team, the icons guidance draft linked above is ready for review @sarah-sch and @finekatie . Thank you!

[sarah-sch]

@jaclinec - content team has finished review. LMK if you have any questions.

[jaclinec]

@annepetersen this is ready for your review - thanks!

[annepetersen]

Reviewed, and my changes are in. Will wait for discussion or acceptance of changes before closing.

[annepetersen]

All set! Assuming we'll need another issue to make these page changes

[annepetersen]

missed a few things