🌟 New: Adds C3.js example
Adds a basic example using C3. Note that C3 doesn't really have a "bubble chart" type, though you can kludge the scatterplot type to work as such. D3 is used for both parsing CSV and scaling the radius value (taken from the D3 example in this repo), which is general practice given D3 is a dependency of C3 anyhow.
C3 is kind of under heavy development at the moment as we pivot to D3 v4; once that happens, a tree-shaken version of D3 will be included in the web bundle and d3-dsv will be recommended for the initial parsing of CSV files.
Should also note, C3 works fine for basic data viz projects but I'd hold off using it for anything really complex (dashboards; data visualisation UIs) until c3js/c3#1843 is resolved.