Add legend to potential pools diagram

[rhyolight]

Use D3js to draw a legend underneath the input space.

[newyork167]

Were you wanting it more like the first image where it is at the bottom (having the extra space under the grid on the left) or did you want to go with something more like the bottom image with the legend to the right (using the empty space that is there)? I wasn't sure if you were wanting to add more information below or to the side or had any preferences.

[rhyolight]

The graphics have a hard width that I cannot exceed, so please put at the bottom, making the diagram taller. Thanks!

[Tyfoods]

Doesn't look like this got finished/added, I made a "Diagram Legends" component. It takes in an array of objects, where each object describes the labels you'd like configured. In this basic case it just takes "label", "fill color", "marker", "markerFillColor".