Polygon:

- Added async methods to polygon.
- The `requests` library is no longer required, with `urllib` being used instead.
- Added the `get_bar_data` function, which returns a dataframe of aggregate data from polygon.
- Opened up the `subscribe` and `unsubscribe` functions

Enhancements:
- Tables will now scroll when the rows exceed table height.

Bugs:
- Fixed a bug preventing async functions being used with horizontal line event.
- Fixed a bug causing the legend to show duplicate lines if the line was created after the legend.
- Fixed a bug causing the line hide icon to persist within the legend after deletion (#75)
- Fixed a bug causing the search box to be unfocused when the chart is loaded.

docs/source/examples/subchart.md

@@ -0,0 +1,50 @@
+# Subcharts
+
+## Grid of 4
+
+```python
+import pandas as pd
+from lightweight_charts import Chart
+
+if __name__ == '__main__':
+    chart = Chart(inner_width=0.5, inner_height=0.5)
+    chart2 = chart.create_subchart(position='right', width=0.5, height=0.5)
+    chart3 = chart.create_subchart(position='left', width=0.5, height=0.5)
+    chart4 = chart.create_subchart(position='right', width=0.5, height=0.5)
+
+    chart.watermark('1')
+    chart2.watermark('2')
+    chart3.watermark('3')
+    chart4.watermark('4')
+
+    df = pd.read_csv('ohlcv.csv')
+    chart.set(df)
+    chart2.set(df)
+    chart3.set(df)
+    chart4.set(df)
+
+    chart.show(block=True)
+
+```
+___
+## Synced Line Chart
+
+```python
+import pandas as pd
+from lightweight_charts import Chart
+
+if __name__ == '__main__':
+    chart = Chart(inner_width=1, inner_height=0.8)
+    chart.time_scale(visible=False)
+
+    chart2 = chart.create_subchart(width=1, height=0.2, sync=True)
+    line = chart2.create_line()
+    
+    df = pd.read_csv('ohlcv.csv')
+    df2 = pd.read_csv('rsi.csv')
+
+    chart.set(df)
+    line.set(df2)
+
+    chart.show(block=True)
+```