Added PrexView service

Added Utilities section & the first service for it (JSON 2 JSONP)

Sometimes a service may not provide its data directly in JSONP for use with client-side JS. This high-availability service (already serving more than 7m requests monthly) can assist in converting data output in JSON to JSONP.

formatting in CONTRIBUTING.md

Discord API isn't only for bots

Add Barchart market data

Add whitepages pro APIs

Add api.ai in Machine Learning section

Add Genderize.io

Added IP Vigilante (https://www.ipvigilante.com/)

and move whitepages API into standalone fraud prevention section

Added Brazil's free zip code api service

Added Official Swiss Public Transport Open Data

There has been some recent interest in adding paid services to this list, so adding `free` in the project's description to clarify the mission of the project.

added newsapi.org

Some quick Googling showed that UIfaces has pretty much wrapped up its life online.

`https://www.file.io` times out, so updating README to reflect loss of HTTPS support.

Data * sections were out of alphabetical order and the Sports/Fitness and Food/Drink sections were not following the `x & y` naming convention.