Nano text editor is always used in this documentation. If you don’t like it you can use a simple editor mcedit which is part of a well-known file manager mc - Midnight Commander. 

mcedit /path/to/file

• F2 - save changes
• F10 - exit without changes Y/N

nano /path/to/file

• Ctrl + x then y - save changes and exit
• Ctrl + x then n - exit without changes