https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet
https://commonmark.org/
Markdown editor ONLINE
https://stackedit.io/
https://dillinger.io/
https://github.com/jbt/markdown-editor -> http://jbt.github.io/markdown-editor/
https://www.textfixer.com/URL
Language code databases
https://zealdocs.org/ - app
https://devdocs.io/ - online
http://martin.hinner.info/geo/ Převod souřadnice | S-JTSK na WGS-84
https://www.onlinevideoconverter.com | Download z YouTube
Spoje.net wiki | https://wiki.spoje.net/doku.php/
ThreeJs | https://threejs.org