Add Pictogram Bar Chart Tested and Improvements

[SimaRaha]

This pull request includes the file plotly-universities-1.ipynb, which demonstrates and tests the pictogram bar chart functionality with various datasets.

[gvwilson]

thanks @SimaRaha - I'll try to get someone to review it as soon as the release we're working on is out the door.

[SimaRaha]

We are currently in the process of developing an improved version.

[gvwilson]

@rl-utility-man believes that this could reasonably be moved into plotly express

[rl-utility-man]

@LiamConnors this is my favorite of the documentation PRs that I have submitted alone and with @SimaRaha over the last six months. Looking forward to getting your feedback at your convenience!