NEW FEATURE: Polygon.io Full integration
- Added `polygon` to the common methods, allowing for data to be pulled from polygon.io. (`chart.polygon.<method>`)
- Added the `PolygonChart` object, which allows for a plug and play solution with the Polygon API.
- Check the docs for more details and examples!
Enhancements:
- Added `clear_markers` and `clear_horizontal_lines` to the common methods.
- Added the `maximize` parameter to the `Chart` object, which maximizes the chart window when shown.
- The Legend will now show Line values, and can be disabled using the `lines` parameter.
- Added the `name` parameter to the `set` method of line, using the column within the dataframe as the value and using its name within the legend.
- Added the `scale_candles_only` parameter to all Chart objects, which prevents the autoscaling of Lines.
- new `screenshot` method, which returns a bytes object of the displayed chart.
Fixes:
- `chart.lines()` now returns a copy of the list rather than the original.
