Improve the `capture` implementation and fix its bugs

[0dminnimda]

• Let Python do its work and use default and regular arguments instead of *args
• Use TypeError instead of AttributeError
• ".png" in "name.png.jpg" will return True, instead we need to check the last four characters
• include_labels is now set to "T" explicitly via capture_labels=True
• Format code for better readability: add new lines after :, add whitespaces around +

[0dminnimda]

@BruceSherwood can you run workflow and review changes please?

[mwcraig]

@0dminnimda -- I can take a look at this later today. I've approved the workflow (really wish that github didn't require that)

[0dminnimda]

I can take a look at this later today

Would be great!

[0dminnimda]

really wish that github didn't require that

Well, there are reasons for this, like make it harder for spammers to send bad code to ci and effectively slow it down for this repo.

But i agree, it's a bit frustrating task to approve those workflows

[0dminnimda]

awaiting for workflow run and merge

[0dminnimda]

oh wait, i think we also should update the docs. tho as i see the docs are not in this repo. so this pr can be merged

[0dminnimda]

One last question -- how would you like to be listed in the list of contributors at https://github.com/vpython/vpython-jupyter/blob/master/CONTRIBUTORS.md ?

under my username - 0dminnimda

[mwcraig]

Excellent, thanks!