Add html_meta to all doc/.md

[Sohlar]

Describe your changes

• Add description, language, and keywords metadata tags to all .md files in doc directory
• Remove empty metadata tag lists in feature_selection.md
• Black formatting in doc/optimization/.
• Update Jupytext version

#TODO: .rst files

Issue ticket number and link

Partially Closes #290

Checklist before requesting a review

• I have performed a self-review of my code
• I have added thorough tests (when necessary).
• I have added the right documentation in the docstring and changelog (when needed)

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📚 Documentation preview 📚: https://sklearn-evaluation--327.org.readthedocs.build/en/327/

[idomic]

@Sohlar tag when ready for review!
Also I think the CI is failing on the docs, please fix.

[coveralls]

Pull Request Test Coverage Report for Build 4563170126

Warning: This coverage report may be inaccurate.

We've detected an issue with your CI configuration that might affect the accuracy of this pull request's coverage report.
To ensure accuracy in future PRs, please see these guidelines.
A quick fix for this PR: rebase it; your next report should be accurate.

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 15 unchanged lines in 4 files lost coverage.
• Overall coverage increased (+0.05%) to 91.718%

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Files with Coverage Reduction	New Missed Lines	%
src/sklearn_evaluation/plot/precision_recall.py	1	98.51%
src/sklearn_evaluation/plot/plot.py	2	72.73%
src/sklearn_evaluation/plot/calibration.py	6	93.02%
src/sklearn_evaluation/plot/roc.py	6	95.11%

Totals
Change from base Build 4469212696:	0.05%
Covered Lines:	3555
Relevant Lines:	3876

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💛 - Coveralls

[edublancas]

note that due to an update in jupyter-book, the html_meta has to appear under the myst section: https://github.com/ploomber/contributing/blob/main/documentation/seo.md

Also if you're the formatting tool, ensure you add notebook_metadata_filter: myst to the metadata, otherwise the metadata is deleted (this is a bug we recently discovered)

more info here: https://github.com/ploomber/contributing/blob/main/documentation/notebooks.md

[edublancas]

FYI: the docs started failing due to an unrelated reason #329 we can either wait for a fix or merge without a doc preview