Vim-tabs is a plugin for Vim that makes writing guitar tablature easier.
You can install vim-tabs using vim-plug by adding Plug 'kanderoo/vim-tabs' to your vimrc and running :PlugInstall. Installation using Pathogen or Vundle might be possible, but I don't use those so I'm not sure.
Tablature in plain text isn't completely standardized, but some norms are present. If you're looking at how to write tab I highly suggest reading through both the wikipedia page on ASCII tab and the Guide To Tab Notation by Howard Wright. The latter especially is a very good resource for a variety of tab styles.