Doctest output simpler version (#7116)

* Update README.md

Added Google Cirq references

* Create barcode_validator.py

Barcode/EAN validator

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* Update barcode_validator.py

Included docstring and updated variables to snake_case

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* Update barcode_validator.py

Included docset and updated bugs

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* Update barcode_validator.py

Implemented the changes asked in review.

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* Update barcode_validator.py

Updated with f-string format

* Update barcode_validator.py

* Update volume_conversions.py

Simpler doctest output

* Update volume_conversions.py

Fixed indentation

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Christian Clauss <cclauss@me.com>