added ctrl-s as save in vim

vimrc

@@ -235,6 +235,10 @@ augroup sourcing
   autocmd bufwritepost .vimrc source $MYVIMRC
 augroup END
 
+noremap <silent> <C-S> :update<CR>
+vnoremap <silent> <C-S> <C-C>:update<CR>
+inoremap <silent> <C-S> <C-O>:update<CR>
+
 " Open file prompt with current path
 nmap <leader>e :e <C-R>=expand("%:p:h") . '/'<CR>