Missing functionality in `px.timeline` against `create_gantt()` figure factory

[saimonduquet]

create_gantt() figure factory is deprecated in favor of px.timeline, but create_gantt() has the feature (argument) group_tasks that is not present with px.timeline.
An additional issue is that the group_task argument is not explained in the create_gantt() documentation check here.

For example, the code:

import plotly.express as px
import pandas as pd

df = pd.DataFrame([
    dict(Task="Job A", Start='2009-01-01', Finish='2009-02-28', Resource='Alex'),
    dict(Task="Job B", Start='2009-03-05', Finish='2009-04-15', Resource='Max'),
    dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30', Resource='Max'),
    dict(Task="Job A", Start='2009-03-02', Finish='2009-05-30', Resource='Alex')
])

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Task", color = "Resource")
fig.update_yaxes(autorange="reversed") # otherwise tasks are listed from the bottom up
fig.show()

Produces:

And I would like to have each tasks in the input data frame into its own line in the y-axis, even for repeating tasks:

We can obtain this using create_gantt() like:

from plotly.figure_factory import create_gantt

fig = create_gantt(df, index_col='Resource', 
                      showgrid_x=True, showgrid_y=True,
                      show_colorbar=True,
                      group_tasks=False
                      )
fig.update_yaxes(autorange="reversed")
fig.show()

Obtaining:

The order follows the order in the df which I found a correct behavior, but an extra input to define the order in create_gantt() would be useful.