Elements of AI course added (FI, DE, EN) (#3502)

* New AI course

* New Finnish AI course

* Elements of AI course in German

* Trailing slash fix

* Trailing slash fix

free-courses-de.md

 ### Index
 
+* [Künstliche Intelligenz](#künstliche-intelligenz)
 * [Python](#python)
 
 
+### Künstliche Intelligenz
+
+* [Elements of AI](https://www.elementsofai.de)
+
+
 ### Python
 
 * [Programmieren lernen mit Python](https://www.youtube.com/playlist?list=PLL1BYAeNY0gzHheN7kCLEhPDegdHrAyDh)

free-courses-en.md

@@ -314,6 +314,7 @@
 * [Bits: The Computer Science of Digital Information](http://www.extension.harvard.edu/open-learning-initiative/bits)
 * [Caltech's Learning From data](https://work.caltech.edu/telecourse.html)
 * [Computer Graphics](http://nptel.ac.in/courses/106106090/)
+* [Elements of AI](https://www.elementsofai.com)
 * [Embedded Software Safety](https://www.youtube.com/playlist?list=PLAQopGWlIcyaqDBW1zSKx7lHfVcOmWSWt) (P. Koopman)
 * [FindLectures.com](https://www.findlectures.com/?class1=Technology) - Index of conference talks by language / topic
 * [LouvainX Paradigms of Computer Programming – Abstraction and Concurrency](https://www.edx.org/course/paradigms-computer-programming-louvainx-louv1-2x-1#!)

free-courses-fi.md

@@ -12,6 +12,7 @@
 
 ### Other
 
+* [Elements of AI](https://www.elementsofai.com/fi/) - Tekoälykurssi
 * [Koodaustunti](http://koodaustunti.fi/miten-aloitan-koodaamaan/) - Opi koodaamaan verkossa
 * [Mooc](https://mooc.fi) - Laadukkaita, avoimia ja ilmaisia verkkokursseja kaikille