survey questions: other languages known (multiselect?)

Hi @dvanrossum, I see you're making progress on the "Other languages known" field for the survey and that it seems to require having a new package dependency (svelte-multiselect) to allow this type of multiselect field.

I wonder if it is worth it (@bridubois, please also give your opinion). I would try to avoid adding dependencies (because of the maintenance and risks for continuous operation in the future they entail), especially for such a niche use. If it would require a new dependency, maybe we can do without that field (it is tricky to analyse anyway). Maybe simplify it a lot, for instance, to a field such as:

• Is there any other language you are relatively fluent in? (If you are fluent in multiple other languages, beyond $target_language and your first language, please select the one closest to $target_language or that seems to help you the most in learning $target_language.) [simple dropdown with languages]
• ($target_language = French if not otherwise specified — this is something that is defined at registration, for the main app users)