v0.2.12: add tooltips to all the things

Version 0.2.12:

Breaking Changes

• removed metrics_markdown() method. Added metrics_descriptions() that
  describes the metric in words.
• removed PredsVsColComponent, ResidualsVsColComponent and ActualVsColComponent,
  these three are now subsumed in RegressionVsColComponent.

New Features

• Added tooltips everywhere throughout the dashboard to explainer
  components, plots, dropdowns and toggles of the dashboard itself.

Improvements

• changed colors on contributions graph and xgboost trees graph: up=green, down=red
  • added higher_is_better parameter. Set to False to switch green and red colors.
• Clarified wording on index selector components
• hiding group cats toggle everywhere when no cats are passed
• passing **kwargs of ExplainerDashbaord down to all all tabs and (sub) components
  so that you can configure components from an ExplainerDashboard param.
  e.g. ExplainerDashboard(explainer, higher_is_better=False).run() will
  pass the higher_is_better param down to all components. In the case of the
  ShapContributionsGraphComponent and the XGBoostDecisionTrees component
  this will cause the red and green colors to flip (normally green is up
  and red is down.)