As you have read my previous article about the "less" command, if you hit the letter "v" when using "less", the default system text editor will be activated to allow you to edit the current file. If you havent defined the default system text editor, vi will be used when you hit "v".
If you want to use another text-editor instead of vi, you will have to change the default system text editor first. To change the default text editor, open the terminal and run the following command:
sudo update-alternatives --config editor
After that, the terminal will display something similar to this (screenshot taken in my Mint box):
As you can see, everything is pretty self-explained here. The default system text editor of Linux Mint is nano. If you still want to keep using nano, just hit enter or close the terminal. If you want to use another text editor, just select the relevant number and hit enter.