Add list of timezone lookup libraries to the README

[evansiroky]

No description provided.

[mattjohnsonpint]

FYI - I've updated the StackOverflow page on this as well.
There are three (yours, mine, and one other) that I've confirmed are using this project's data. If you know of any others, please let me know. 😄

[evansiroky]

Nice! I do know that https://github.com/darkskyapp/tz-lookup/ also uses this project's data.

[mattjohnsonpint]

Cool. Added it.

[simonw]

I just built https://timezones-api.now.sh/timezones/by_point using this data. I have an extensive write-up describing how I built it here: https://simonwillison.net/2017/Dec/12/building-a-location-time-zone-api/

[simonw]

Here's an example of a page that renders one of the shapes using Leaflet and GeoJSON: https://timezones-api.now.sh/timezones-4fbc08f/timezones/342

[BertoldVdb]

I needed to lookup the timezone based on GPS coordinates in an embedded system. I did not find a C/C++ library so I made my own: https://github.com/BertoldVdb/ZoneDetect