Frontend Web (chart-example repo) lesson has some extra stuff

[dmil]

Instructions that reference this are not extraneous

var svg = d3.select("body").append("svg")
 .attr("width", width + margin.left + margin.right)
 .attr("height", height + margin.top + margin.bottom)
 .attr("class", "chart")
 .attr("id", "apple-stock-chart")

Also, I might consider introducing the "inspect element" window in the browser more formally, especially if we plan to explore snippets like the one above.