Small multiples

This is a re-implementation of this neat small mutliple example using d3fc components.

Some notable things ...

• The area, line and point series renderers remove some of the basic SVG rendering logic.
• The cartesian chart component is being rendered via a data-join to create the small multiples. Because the chart uses a mixture of SVG and DOM, we can hide the y axis for repeated charts using CSS.
• The responsive behaviour where the chart height is reduced for narrower screens uses a simple media query. This is made possible because the chart components uses the underlying d3fc element API which handles redrawing svg / canvas elements when their size changes.