Add futurecoder (#6734)

* Add futurecoder

* Trailing slash

* Tweak futurecoder entry

Co-authored-by: ImVector <59611597+LuigiImVector@users.noreply.github.com>

Co-authored-by: ImVector <59611597+LuigiImVector@users.noreply.github.com>

more/free-programming-interactive-tutorials-en.md

@@ -312,6 +312,7 @@
 
 * [Codecademy Python course](https://www.codecademy.com/learn/python)
 * [Data Analysis with Python Certification](https://www.freecodecamp.org/learn/data-analysis-with-python/) - freeCodeCamp
+* [Futurecoder](https://futurecoder.io) - Alex Hall
 * [How to Think Like a Computer Scientist: Learning with Python, Interactive Edition](http://interactivepython.org/courselib/static/thinkcspy/index.html)
 * [Learn Python](http://www.learnpython.org)
 * [Learn Python Step by Step](http://www.techbeamers.com/python-tutorial-step-by-step)