Drop unused function key mappings

dotfiles/vim/vimrc

@@ -70,9 +70,7 @@ set directory+=.
 
 set updatetime=100
 set t_vb=
-noremap <F2> :set list!<CR>
 set pastetoggle=<F4>
-nmap <F3> :set invnumber<CR>
 
 if has('mouse')
   set mouse=a