[Feature request] Configuration option for modernbindings

[theaz7ieth5e]

I would like to enable the modern bindings by default on my machines, 
however, currently the only way to switch them on is to pass a flag (-/, 
--modernbindings). I want running `editor` or `nano` to always use the 
modern bindings, so I made `nano` an alias to `nano -/` in my shell, but 
this doesn't work all the time—running `sudo editor` or `systemctl edit` 
bypasses the shell. I'd like to propose a nanorc config line that 
enables modern bindings, such as `set modernbindings`.