TP Data Viz - dynamic line chart
A dynamic line chart plots a synthetic dataset of monthly values from January to December 2016, where hovering over a circular point highlights it in red, shows the value in a text tooltip, and draws a dashed vertical guide to the baseline. The chart uses an ordinal x-scale for categories and a linear y-scale, with the line, circles, and labels rendered as SVG elements. Built with D3 v3, it loads data from a JSON file via `d3.json`, applies date parsing with `d3.time.format`, and uses mouseover and mouseout events to toggle the interactive annotations.