vim: vim-startify: add open dir command

etc/soft/vim/vimrc

@@ -884,7 +884,8 @@ let g:startify_bookmarks = [
 	\ ]
 
 let g:startify_commands = [
-        \ {'m': ['$ make', 'make']},
+        \ {'d': ['Open current directory (GUI)', 'silent exec "!x-open ."']},
+        \ {'m': ['Make current project ($ make)', 'make']},
         \ ]
 
 let g:ascii = systemlist("git-cal --unicode 2>/dev/null | grep -v fatal || echo")