Doc: add cowsay() example

doc/startify.txt

@@ -955,19 +955,22 @@ This is my configuration..
     let g:startify_session_persistence    = 1
 
     let g:startify_skiplist = [
-                \ 'COMMIT_EDITMSG',
-                \ 'bundle/.*/doc',
-                \ '/data/repo/neovim/runtime/doc',
-                \ '/Users/mhi/local/vim/share/vim/vim74/doc',
-                \ ]
+            \ 'COMMIT_EDITMSG',
+            \ 'bundle/.*/doc',
+            \ '/data/repo/neovim/runtime/doc',
+            \ '/Users/mhi/local/vim/share/vim/vim74/doc',
+            \ ]
 
     let g:startify_bookmarks = [
-                \ { 'c': '~/.vim/vimrc' },
-                \ '~/golfing',
-                \ ]
+            \ { 'c': '~/.vim/vimrc' },
+            \ '~/golfing',
+            \ ]
+
+    let g:startify_custom_header =
+            \ startify#fortune#cowsay('═','║','╔','╗','╝','╚')
 
     let g:startify_custom_footer =
-          \ ['', "   Vim is charityware. Please read ':help uganda'.", '']
+           \ ['', "   Vim is charityware. Please read ':help uganda'.", '']
 
     hi StartifyBracket ctermfg=240
     hi StartifyFile    ctermfg=147