index.js

var path = 'atom-electron-b4403fa/docs/api/accelerator.md'
// wanted: 'docs/latest/api/accelerator'
// - add 'latest/' after 'docs/'
// - remove 'atom-electron-b443fa'
// - remove file extension at the end

function constructRedirectUrl (path) {
  var a = path.split('/')
  a.splice(2, 0, 'latest').splice(0, 1)
  var c = a.join('/')
  var d = c.split('.')
  return d.shift()
}