Docs: Methodology section

[benjaoming]

• Adds a methodology section with 2 articles that we have had in the making for a while
• Proposes to cross-reference best-practice into this section because the two topics seem very tightly coupled

Note the separate effort to shorten the Explanation top-level in #10416

Refs: #9747

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📚 Documentation previews 📚

• User's documentation (docs): https://docs--10417.org.readthedocs.build/en/10417/

• Developer's documentation (dev): https://dev--10417.org.readthedocs.build/en/10417/