Add appropriate copyright and attribution to code extracted from bootstrapped and pingouin

[bikegeek]

Describe the Task

Bootstrapped
the Python bootstrapped code needs to follow the attribution rules:
https://github.com/facebookarchive/bootstrapped/blob/master/LICENSE

pingouin
the Python pingouin code needs to follow these attribution rules:
Pingouin is licensed under the GNU General Public License v3.0 (GPL-3), which is less permissive than the BSD or MIT licenses. The reason for this is that Pingouin borrows extensively from R packages, which are all licensed under the GPL-3. To read more about what you can do and cannot do with a GPL-3 license, please visit tldrlegal.com or choosealicense.com.
https://tldrlegal.com/license/gnu-general-public-license-v3-(gpl-3)#summary

Just in case we need to do the same for statsmodels (if NCO doesn't permit installation of the statsmodels package), here is the copyright/attribution information:
https://github.com/statsmodels/statsmodels/blob/main/COPYRIGHTS.txt

https://opensource.org/licenses/BSD-3-Clause

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