Rename a few options

[thiswillbeyourgithub]

Is your feature request related to a problem? Please describe.
When creating a new shortcut every few weeks it's a headache to figure out which button is the correct one.
It is related to the bug report I did 30 minutes ago where I didn't know that "save" was not the correct button to press but "set".

Describe the solution you'd like
In the reading option, in the tab named "quick keys" :
rename the following button :
new -> reset fields
set -> create/update quick key
unset -> delete quick key

[jdlorimer]

This might actually be a good idea. I'll have a think about it. Thanks!