Update WebThings description and links

Mozilla has spun out WebThings into a community-owned project.

See: https://hacks.mozilla.org/2020/12/flying-the-nest-webthings-gateway-1-0/

README.md

@@ -873,11 +873,11 @@ _Games, game servers and control panels._
 - [FHEM](https://fhem.de/fhem.html) - FHEM is used to automate common tasks in the household like switching lamps and heating. It can also be used to log events like temperature or power consumption. You can control it via web or smartphone frontends, telnet or TCP/IP directly. ([Source Code](https://svn.fhem.de/trac)) `GPL-3.0` `Perl`
 - [Gladys](https://gladysproject.com) - Gladys is an open-source home assistant which runs on your Raspberry Pi. ([Source Code](https://github.com/GladysProject/Gladys)) `MIT` `Nodejs`
 - [Home Assistant](https://home-assistant.io/) - Open-source home automation platform. ([Demo](https://home-assistant.io/demo/), [Source Code](https://github.com/home-assistant/home-assistant)) `MIT` `Python`
-- [Mozilla Gateway](https://iot.mozilla.org/gateway/) - Mozilla WebThings is Mozilla’s open source implementation of the Web of Things, including the WebThings Gateway and the WebThings framework. ([Source Code](https://github.com/mozilla-iot/gateway)) `MPL-2.0` `NodeJS`
 - [Node RED](http://nodered.org/) - Browser-based flow editor that helps you wiring hardware devices, APIs and online services to create IoT solutions. ([Source Code](https://github.com/node-red/node-red)) `Apache-2.0` `Nodejs`
 - [openHAB](http://www.openhab.org) - Vendor and technology agnostic open source software for home automation. ([Demo](http://demo.openhab.org:8080/), [Source Code](https://github.com/openhab/openhab)) `EPL-2.0` `Java`
 - [Thingsboard](https://thingsboard.io/) - Open-source IoT Platform - Device management, data collection, processing and visualization. ([Demo](https://demo.thingsboard.io/signup), [Source Code](https://github.com/thingsboard/thingsboard)) `Apache-2.0` `Java`
 - [Thingspeak](https://thingspeak.com/) - Open source “Internet of Things” application and API to store and retrieve data from things using HTTP. ([Demo](https://thingspeak.com/channels/public), [Source Code](https://github.com/iobridge/thingspeak)) `GPL-3.0` `Ruby`
+- [WebThings Gateway](https://webthings.io/gateway/) - WebThings is an open source implementation of the Web of Things, including the WebThings Gateway and the WebThings Framework. ([Source Code](https://github.com/WebThingsIO/gateway)) `MPL-2.0` `NodeJS`
 
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