added information about multiple env vars
added information about multiple env vars

Also corrected a missing do and added a not that on is required for the dsl. Added an example of the with syntax taking multiple env vars.
capistrano/capistrano,harrykiselev/capistrano,maliqq/capistrano,harrykiselev/capistrano,capistrano/capistrano,maliqq/capistrano