Adding changedetection.io (#2408)

Adding changedetection.io

README.md

@@ -1035,6 +1035,7 @@ _See also <https://en.wikipedia.org/wiki/List_of_streaming_media_systems>, <http
 - [blynk](https://blynk.io/) - Platform with iOS and Android apps to control Arduino, ESP8266, Raspberry Pi and similar microcontroller boards over the Internet. ([Source Code](https://github.com/blynkkk/blynk-server)) `AGPL-3.0` `Java`
 - [Cachet](https://cachethq.io/) - An open source status page system for everyone. ([Demo](https://demo.cachethq.io/), [Source Code](https://github.com/CachetHQ/Cachet)) `BSD-3-Clause` `PHP`
 - [CapRover](https://caprover.com/) - Build your own PaaS in a few minutes. ([Demo](https://captain.server.demo.caprover.com/#/login), [Source Code](https://github.com/caprover/caprover)) `Apache-2.0` `Docker/Nodejs`
+- [changedetection.io](https://github.com/dgtlmoon/changedetection.io) - Self-hosted tool for staying up-to-date with web-site content changes. `Apache-2.0` `Python/Docker`
 - [cState](https://github.com/cstate/cstate/) - Static status page for hyperfast Hugo. Clean design, minimal JS, super light HTML/CSS, high customization, optional admin panel, read-only API, IE8+. Best used with Netlify, Docker. ([Demo](https://cstate.mnts.lt/)) `MIT` `Go`
 - [CUPS](https://www.cups.org/) - The Common Unix Print System uses Internet Printing Protocol (IPP) to support printing to local and network printers. ([Source Code](https://github.com/apple/cups)) `GPL-2.0` `C`
 - [CyberChef](https://github.com/gchq/CyberChef) - Perform all manner of "cyber" operations within a web browser such as AES, DES and Blowfish encryption and decryption, creating hexdumps, calculating hashes, and much more. ([Demo](https://gchq.github.io/CyberChef)) `Apache-2.0` `JavaScript`