Added IP2WHOIS API

Added QWeather in README.md

Add catAPI

Russian State Duma Open Data

Added Dark Souls 3 API

Adds shrtlnk.dev url shortener

Add localizr API

Add a RESTful free API to check the weather

Add 'User-Agent' to the auth_keys array in the validate_format script

Add BigDataCloud API for IP and Geolocation

Added Etsy API

Adds Humble Bundle API

Bump httplib2 from 0.18.0 to 0.19.0 in /build

Add Spoonacular Food API

Added zip codes and streets from Brazil API

Update to Meteorologisk Institutt API.

Add Giant Bomb API

add cryptomarket api - cryptocurrency exchange api

Indeed has discontinued their API. See https://stackoverflow.com/a/66036140/13752077

The PR #1610 added an duplicate link to the government section

Added 1 api in the Government category

Add API la Data Verte - Environment topic

Add MLB API

Add UK government API catalogue

The PR #1610 added an extra blank line

Add Blitapp

Added US census data api

This isn't an API but rather the site where they are collated by the UK
government.

I've added the data.gov.uk site as a separate entry for clarity (because
of the number of similar sites from other countries). This site is also
linked to from the API catalogue site.