Add CoffeeScript for the bar chart diagram
user
```coffeescript
#=require d3
$ ->
  
  margin = {
    top:    20,
    right:  20,
    bottom: 30,
    left:   40
  }

  width = 960 - margin.left - margin.right
  height = 500 - margin.top - margin.bottom

  formatPercent = d3.format(".0%")
  x = d3.scale.ordinal()
    .rangeRoundBands([0, width], 0.1, 1)

  y = d3.scale.linear()
    .range([height, 0])

  xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom")

  yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
    .tickFormat(formatPercent)

  svg = d3.select(".dashboard").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
    .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")")

  gon.data.forEach (d) ->
    d.frequency = +d.frequency

  x.domain gon.data.map (d) -> return d.format.toUpperCase()
  y.domain([0, d3.max(gon.data, (d) -> return d.frequency)])

  svg.append("g")
    .attr("class", "x axis")
    .attr("transform", "translate(0," + height + ")")
    .call(xAxis)

  svg.append("g")
    .attr("class", "y axis")
    .call(yAxis)
    .append("text")
    .attr("transform", "rotate(-90)")
    .attr("y", 6)
    .attr("dy", ".71em")
    .style("text-anchor", "end")
    .text("Frequency")

  svg.selectAll(".bar")
    .data(gon.data)
    .enter().append("rect")
    .attr("class", "bar")
    .attr("x", (d) -> return x(d.format))
    .attr("width", x.rangeBand())
    .attr("y", (d) -> y(d.frequency))
    .attr("height", (d) -> return height - y(d.frequency))

  d3.select("button").on "click", () ->
    console.log "yep"

    x0 = x.domain(gon.data.sort(if true then (a, b) -> return (b.frequency - a.frequency)
    else (a, b) -> return (d3.ascending(a.format, b.format)))
      .map((d) -> return d.format))
      .copy()


    transition = svg.transition().duration(750)
    delay = (d, i) -> i * 50

    transition.selectAll(".bar")
      .delay(delay)
      .attr("x", (d) -> x0(d.format))

    transition.select(".x.axis")
      .call(xAxis)
      .selectAll("g")
      .delay(delay)
```
assistant