Add additional chart information to to PJs

Description

PJs doesn't include all chart options available from within gitlab-ui.

Examples

https://design.gitlab.com/components/charts#types only mentions column charts, line charts, and area charts.

In addition to these, we also have:

• Scatter chart
  • https://gitlab-org.gitlab.io/gitlab-ui/?path=/story/charts-discrete-scatter-chart--default
• Heatmap
  • https://gitlab-org.gitlab.io/gitlab-ui/?path=/story/charts-heatmap--default

Column charts also support a click interaction - I don't actually think that this is explicitly mentioned in gitlab-ui either.

Additional information

This was raised in discussion over here #541 (comment 333095362)