Feedback modal: employ concrete asks

On the Learning team call today, I asked what kind of information we should be including in the modal. They really liked the simplicity of how Firefox used to ask for feedback (seen here-- it's an older release and I believe they don't do it anymore): https://pinterest.com/pin/159314905539543771/

We could break up the feedback area into two boxes:

:) Webmaker makes me happy because :_________________________________

:( Webmaker makes me sad because:____________________________________

They also felt that we needed to include more friendly visuals and "fun language" here. They gave this as a refernce: https://pinterest.com/pin/159314905539543686/

Perhaps in the future we could get some help with copywriting to lighten up our language.

No files or tests are named. Start by locating the existing feedback modal, review the two referenced examples, and clarify the desired copy, visual treatment, and acceptance criteria before implementing the two feedback prompts.

Written by the indexing model from the issue text.