update notebook

[andrewgsavage]

• [x] Closes #9 #43
• [x] Executed pre-commit run --all-files with no errors
• [x] The change is fully covered by automated unit tests
• [x] Documented in docs/ as appropriate
• [x] Added an entry to the CHANGES file

Updates notebook to show plotting in pandas 1.3 Adds a line in the notebook documenting https://github.com/hgrecco/pint-pandas/pull/104

[andrewgsavage]

bors r+

[bors[bot]]

Build failed:

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[andrewgsavage]

bors r+

[bors[bot]]

Build succeeded:

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