add pronunciation to README (#5336)
## Summary
Adds an IPA pronunciation to the very top of the README, for the sake of
clarity. This is a minor thing, but it's nice to know that there's a
'standard' pronunciation for uv.
I have no idea whether this will seem like a "reasonable" place to put
this; I looked over the README and didn't see any obviously more
appropriate places to put it. Maybe this is unobtrusive enough that it's
fine where it is; maybe there should be a new section added somewhere;
maybe somebody who has a better feel for the project goals will have a
clever suggestion.
Closes #5309
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Co-authored-by: Zanie Blue <contact@zanie.dev>
