Graph code should be in this repo

[rtoy]

The code that was used to produce the graphs in https://webaudio.github.io/web-audio-api/#computation-of-value and https://webaudio.github.io/web-audio-api/#example1-AudioParam should be included in this repository so that it can be easily managed and edited as part of the spec.

[rtoy]

The graph code uses flot. Not sure if we want to include a copy of that as well, but it's needed for generating these plots.

[mdjp]

If there are no issues with including flot then it seems like a sensible option.