Fix rendering in documentation of histogram histfunc

[JasonGross]

Previously it rendered as

Now there should be a space after the period in "'max'.Function used to aggregate should render as" and the final sentence should render as

The arguments to this function are the values of y (x) if orientation is 'v' ('h').

Documentation PR

• I've seen the doc/README.md file
• This change runs in the current version of Plotly on PyPI and targets the doc-prod branch OR it targets the master branch
• [] If this PR modifies the first example in a page or adds a new one, it is a px example if at all possible
• [] Every new/modified example has a descriptive title and motivating sentence or paragraph
• [] Every new/modified example is independently runnable
• [] Every new/modified example is optimized for short line count and focuses on the Plotly/visualization-related aspects of the example rather than the computation required to produce the data being visualized
• [] Meaningful/relatable datasets are used for all new examples instead of randomly-generated data where possible
• [] The random seed is set if using randomly-generated data in new/modified examples
• [] New/modified remote datasets are loaded from https://plotly.github.io/datasets and added to https://github.com/plotly/datasets
• [] Large computations are avoided in the new/modified examples in favour of loading remote datasets that represent the output of such computations
• [] Imports are plotly.graph_objects as go / plotly.express as px / plotly.io as pio
• [] Data frames are always called df
• [] fig = <something> call is high up in each new/modified example (either px.<something> or make_subplots or go.Figure)
• [] Liberal use is made of fig.add_* and fig.update_* rather than go.Figure(data=..., layout=...) in every new/modified example
• [] Specific adders and updaters like fig.add_shape and fig.update_xaxes are used instead of big fig.update_layout calls in every new/modified example
• [] fig.show() is at the end of each new/modified example
• [] plotly.plot() and plotly.iplot() are not used in any new/modified example
• [] Hex codes for colors are not used in any new/modified example in favour of these nice ones

[Coding-with-Adam]

Thank you for this PR, @JasonGross . Updates look good to me.
@LiamConnors do you know why the release_build test failed?

[LiamConnors]

Hi @Coding-with-Adam. yes there was an issue with conda-build and it's resolved now on doc-prod
#4509. We just need to merge the latest changes ondoc-prod into this branch and the tests should pass.

[JasonGross]

I've rebased

[JasonGross]

CI passes

[archmoj]

💃