Improve markdown folding & syntax highlights

after/ftplugin/markdown.vim

@@ -3,6 +3,36 @@ if !has("win32") || has("gui_running")
   setlocal spell
 endif
 
+setlocal foldmethod=expr
+setlocal foldexpr=MarkdownFold(v:lnum)
+
+function! MarkdownFold(lnum)
+  let l:line = getline(a:lnum)
+
+  if match(l:line, '^######.*$') == 0
+    return '>6'
+  elseif match(l:line, '^#####.*$') == 0
+    return '>5'
+  elseif match(l:line, '^####.*$') == 0
+    return '>4'
+  elseif match(l:line, '^###.*$') == 0
+    return '>3'
+  elseif match(l:line, '^##.*$') == 0
+    return '>2'
+  elseif match(l:line, '^#.*$') == 0
+    return '>1'
+  endif
+
+  return '='
+endfunction
+
+hi link markdownCode Special
+hi link markdownCodeDelimiter PreProc
+hi link markdownHeadingDelimiter Statement
+hi link markdownLinkDelimiter PreProc
+hi link markdownLinkTextDelimiter PreProc
+hi link markdownUrl Include
+
 " Max 80 chars wide.
 setlocal textwidth=80
 " Use tabwidth of 4 to be markdown complient.

vimrc

@@ -157,9 +157,6 @@ let g:DoxygenToolkit_commentType="C++"
 
 " markdown live browser preview
 Plug 'suan/vim-instant-markdown'
-
-" markdown folding
-Plug 'nelstrom/vim-markdown-folding'
 let g:markdown_fenced_languages=['cpp', 'c', 'cmake', 'sh', 'vim', 'python']
 
 " SimplyFold - python folding