Add FHEM

Resolves #1027.

The license is based on this file: https://svn.fhem.de/trac/browser/trunk/fhem/docs/copyright?rev=2103. I do have concerns as I have seen trademarked/copyright written in a few places.

README.md

@@ -124,6 +124,7 @@ _Business Intelligence_
   * [bip.io](https://bip.io/) - Web Automation For People And Robots - Drag, Drop, and Connect The Services You Love. ([Source Code](https://github.com/bipio-server/bipio)) `GPLv3` `Nodejs`
   * [CouchPotato](https://couchpota.to/) - CouchPotato is an automatic Video Library Manager for Movies. Automatic torrent/nzb searching, downloading, and processing at the qualities you want. ([Source Code](https://github.com/CouchPotato/CouchPotatoServer/)) `GPLv3` `Python`
   * [Episodes](https://github.com/guptachetan1997/Episodes) - `⚠` Self Hosted TV show Episode tracker and recommender built using django, bootstrap4. `MIT` `Python`
+  * [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)) `GPLv3` `Perl`
   * [Headphones](https://github.com/rembo10/headphones) - An automated music downloader for NZB and Torrent, written in Python. It supports SABnzbd, NZBget, Transmission, µTorrent, Deluge and Blackhole. `GPLv3` `Python`
   * [Healthchecks](https://healthchecks.io/) - Django app which listens for pings and sends alerts when pings are late. ([Source Code](https://github.com/healthchecks/healthchecks)) `BSD` `Python`
   * [Home Assistant](https://home-assistant.io/) - An open-source home automation platform. ([Demo](https://home-assistant.io/demo/), [Source Code](https://github.com/home-assistant/home-assistant)) `MIT` `Python`