Add xkcd style template for plotly

[RatanShreshtha]

I have been using plotly.py for a while now and I love this library as it is a delight to use and plots are so beautiful.

I recently got know about the themes and templates in plotly.py and I wish there was one option for making plots look like xkcd comics.

import plotly.io as pio
pio.templates

Templates configuration
-----------------------
    Default template: 'plotly'
    Available templates:
        ['ggplot2', 'seaborn', 'simple_white', 'plotly',
         'plotly_white', 'plotly_dark', 'presentation', 'xgridoff',
         'ygridoff', 'gridon', 'xkcd', 'none']

And can be used in plots like below

import plotly.express as px

df = px.data.gapminder()
df_2007 = df.query("year==2007")

fig = px.scatter(df_2007,
                     x="gdpPercap", y="lifeExp", size="pop", color="continent",
                     log_x=True, size_max=60,
                     template="xkcd", title="Gapminder 2007: 'xkcd' theme")
fig.show()

[gvwilson]

Hi - we are trying to tidy up the stale issues and PRs in Plotly's public repositories so that we can focus on things that are still important to our community. Since this one has been sitting for several years, I'm going to close it; if it is still a concern, please add a comment letting us know what recent version of our software you've checked it with so that I can reopen it and add it to our backlog. Thanks for your help - @gvwilson