vim: add macvim config

vim/vimrc

@@ -136,11 +136,14 @@ endif
 
 " OS-specific settings
 if has('gui_running')
-   if has('win32')
+   if has('gui_win32')
       set guifont=PxPlus_IBM_EGA8:h12:cDEFAULT:qDRAFT
-   else
+   elseif has('gui_gtk')
       set guifont=PxPlus\ IBM\ EGA8\ 12
       set linespace=-2
+   elseif has('gui_macvim')
+      set guifont=IBMPlexMono-Text:h14
+      set linespace=-3
    endif
 endif