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/table.md

@@ -0,0 +1,38 @@
+# Table
+
+```python
+import pandas as pd
+from lightweight_charts import Chart
+
+def on_row_click(row):
+    row['PL'] = round(row['PL']+1, 2)
+    row.background_color('PL', 'green' if row['PL'] > 0 else 'red')
+
+    table.footer[1] = row['Ticker']
+
+if __name__ == '__main__':
+    chart = Chart(width=1000, inner_width=0.7, inner_height=1)
+    subchart = chart.create_subchart(width=0.3, height=0.5)
+    df = pd.read_csv('ohlcv.csv')
+    chart.set(df)
+    subchart.set(df)
+
+    table = chart.create_table(width=0.3, height=0.2,
+                  headings=('Ticker', 'Quantity', 'Status', '%', 'PL'),
+                  widths=(0.2, 0.1, 0.2, 0.2, 0.3),
+                  alignments=('center', 'center', 'right', 'right', 'right'),
+                  position='left', func=on_row_click)
+
+    table.format('PL', f'£ {table.VALUE}')
+    table.format('%', f'{table.VALUE} %')
+
+    table.new_row('SPY', 3, 'Submitted', 0, 0)
+    table.new_row('AMD', 1, 'Filled', 25.5, 105.24)
+    table.new_row('NVDA', 2, 'Filled', -0.5, -8.24)
+
+    table.footer(2)
+    table.footer[0] = 'Selected:'
+
+    chart.show(block=True)
+
+```