Brunel 2.6 Feature request: allow location in syntax legend()

[cjiang-ibm]

Currently, the legend location is always in the top-right side of the chart.
Sometime, we want to put the legend at the top/bottom of the chart.
Please add this feature in future release.

[grahamwills]

I have added experimental code: syntax is legends(floating) that chooses a good place inside the chart. This might help