message: Add support for non-alphanumeric/symbol characters in channel index group headers
diff: extends ../../../components/layout/index
  block body
  - - var range = '!~@#$%^&*()_-+=<>.,?/ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('')
  - - range.unshift('0-9')
  -
  include _path
  include _tips
  - if _.keys(alpha).length
  + - var alphaKeys = _.sortBy(_.keys(alpha))
  + if alphaKeys.length
  .channel-container.flex-container.channel-container--alpha
  .alpha(class=channelsCount > 10 ? "alpha--two-columns" : "")
  - for letter in range
  + for letter in alphaKeys
  - group = alpha[letter]
  if group
  .alpha__group
  