Revert "changed markdown_preview plugin to hammer because author changed project name and rake was failing on it"
Revert "changed markdown_preview plugin to hammer because author changed project name and rake was failing on it"

This reverts commit 2fbe282ae849504829af98c2b7f61f451903fd15.

tantion/vim,faun/dotfiles,faun/dotfiles,defn/junas,tantion/vim