This plugin enables folding by section headings in markdown documents.
I recommend installing markdown-folding using pathogen or Vundle. Your vimrc file must contain these lines at the very least:
set nocompatible
if has("autocmd")
filetype plugin indent on
endif
The markdown-folding plugin provides nothing more than a foldexpr for markdown files. If you want syntax highlighting and other niceties, then go and get tpope's vim-markdown plugin.
Copyright (c) Drew Neil. Distributed under the same terms as Vim itself.
See :help license.