Enhancements and Bug Fixes

Tables Feature
- Added the `create_table` method, which returns a `Table` object. This can be used to display watchlists, order windows, position windows and more.
- See the new page on the docs for more information!

Bugs
- Fixed a bug preventing the named column of a line to not work as a label of the series.
- Fixed a bug causing drawings loaded from the minute timeframe to not show on a daily timeframe.
- Fixed a bug causing `chart.exit` to not work.
- Fixed a bug preventing the chart from being moved after placing a ray.
- Fixed the ‘price in hoveringOver’ web console error.

Enhancements
- The date/time column can also be the `name` of the passed series object.
- Added the `label` method to `HorizontalLine`, allowing for the price line label of horizontal lines to be updated.
- `None` or an empty DataFrame can now be passed to `line.set` as a means to clear it.
- Seperate Chart objects will now run on the same pywebview instance. This means that any Chart objects created after the first will inherit the first Chart’s API.
- Reorganized the documentation for clarity.

docs/source/callbacks.md

@@ -0,0 +1,132 @@
+# Callbacks
+
+The `Chart` object allows for asynchronous and synchronous callbacks to be passed back to python, allowing for more sophisticated chart layouts including searching, timeframe selectors text boxes, and hotkeys using the `add_hotkey` method.
+
+`QtChart`and `WxChart` can also use callbacks.
+
+A variety of the parameters below should be passed to the Chart upon decaration.
+* `api`: The class object that the fixed callbacks will always be emitted to.
+* `topbar`: Adds a [TopBar](#topbar) to the `Chart` or `SubChart` and allows use of the `create_switcher` method.
+* `searchbox`: Adds a search box onto the `Chart` or `SubChart` that is activated by typing.
+
+___
+## How to use Callbacks
+
+Fixed Callbacks are emitted to the class given as the `api` parameter shown above.
+
+Take a look at this minimal example:
+
+```python
+class API:
+    def __init__(self):
+        self.chart = None
+
+    def on_search(self, string):
+        print(f'Search Text: "{string}" | Chart/SubChart ID: "{self.chart.id}"')
+```
+Upon searching in a pane, the expected output would be akin to:
+```
+Search Text: "AAPL" | Chart/SubChart ID: "window.blyjagcr"
+```
+The ID shown above will change depending upon which pane was used to search, due to the instance of `self.chart` dynamically updating to the latest pane which triggered the callback.
+`self.chart` will update upon each callback, allowing for access to the specific pane in question.
+
+```{important}
+* When using `show` rather than `show_async`, block should be set to `True` (`chart.show(block=True)`).
+* `API` class methods can be either coroutines or normal methods.
+* Non fixed callbacks (switchers, hotkeys) can be methods, coroutines, or regular functions.
+```
+
+There are certain callbacks which are always emitted to a specifically named method of API:
+* Search callbacks: `on_search`
+* Interactive Horizontal Line callbacks: `on_horizontal_line_move`
+
+___
+
+## `TopBar`
+The `TopBar` class represents the top bar shown on the chart when using callbacks:
+
+![topbar](https://i.imgur.com/Qu2FW9Y.png)
+
+This class is accessed from the `topbar` attribute of the chart object (`chart.topbar.<method>`), after setting the topbar parameter to `True` upon declaration of the chart.
+
+Switchers and text boxes can be created within the top bar, and their instances can be accessed through the `topbar` dictionary. For example:
+
+```python
+chart = Chart(api=api, topbar=True)
+
+chart.topbar.textbox('symbol', 'AAPL') # Declares a textbox displaying 'AAPL'.
+print(chart.topbar['symbol'].value) # Prints the value within ('AAPL')
+
+chart.topbar['symbol'].set('MSFT') # Sets the 'symbol' textbox to 'MSFT'
+print(chart.topbar['symbol'].value) # Prints the value again ('MSFT')
+```
+___
+
+### `switcher`
+`name: str` | `method: function` | `*options: str` | `default: str`
+
+* `name`: the name of the switcher which can be used to access it from the `topbar` dictionary.
+* `method`: The function from the `api` class given to the constructor that will receive the callback.
+* `options`: The strings to be displayed within the switcher. This may be a variety of timeframes, security types, or whatever needs to be updated directly from the chart.
+* `default`: The initial switcher option set.
+___
+
+### `textbox`
+`name: str` | `initial_text: str`
+
+* `name`: the name of the text box which can be used to access it from the `topbar` dictionary.
+* `initial_text`: The text to show within the text box.
+___
+
+## Callbacks Example:
+
+```python
+import pandas as pd
+from lightweight_charts import Chart
+
+
+def get_bar_data(symbol, timeframe):
+    if symbol not in ('AAPL', 'GOOGL', 'TSLA'):
+        print(f'No data for "{symbol}"')
+        return pd.DataFrame()
+    return pd.read_csv(f'../examples/6_callbacks/bar_data/{symbol}_{timeframe}.csv')
+
+
+class API:
+    def __init__(self):
+        self.chart = None  # Changes after each callback.
+
+    def on_search(self, searched_string):  # Called when the user searches.
+        new_data = get_bar_data(searched_string, self.chart.topbar['timeframe'].value)
+        if new_data.empty:
+            return
+        self.chart.topbar['symbol'].set(searched_string)
+        self.chart.set(new_data)
+
+    def on_timeframe_selection(self):  # Called when the user changes the timeframe.
+        new_data = get_bar_data(self.chart.topbar['symbol'].value, self.chart.topbar['timeframe'].value)
+        if new_data.empty:
+            return
+        self.chart.set(new_data, True)
+
+    def on_horizontal_line_move(self, line_id, price):
+        print(f'Horizontal line moved to: {price}')
+
+
+if __name__ == '__main__':
+    api = API()
+
+    chart = Chart(api=api, topbar=True, searchbox=True, toolbox=True)
+    chart.legend(True)
+
+    chart.topbar.textbox('symbol', 'TSLA')
+    chart.topbar.switcher('timeframe', api.on_timeframe_selection, '1min', '5min', '30min', default='5min')
+
+    df = get_bar_data('TSLA', '5min')
+    chart.set(df)
+
+    chart.horizontal_line(200, interactive=True)
+
+    chart.show(block=True)
+```