docs: function mergeAdjacent (markups) {
    var i
  
    for (i = 0; i < markups.length - 1; i += 1) {
      if (!canMerge(markups[i], markups[i + 1]))
        continue
  
      markups[i].end = Math.max(markups[i].end, markups[i + 1].end)
      markups.splice(i + 1, 1)
      i -= 1
    }
  }