Align SCCM technique mappings and matrix; add CSV source of truth

[DocumentationDave]

Summary

This PR aligns the SCCM Attack & Defense Matrix with the technique documentation by correcting mappings and fixing link issues. It also adds a CSV version of the matrix for easier full-width viewing in GitHub and help maintain future updates.

Changes

• Updated links/associations between attack and defensive techniques to ensure mappings are bidirectional where the documentation already implied the relationship.
• Updated the Attack & Defense Mapping Matrix to match the corrected technique mappings; removed incorrect (or no longer applicable) mappings.
• Added a CSV version of the matrix for easier viewing/navigation, and linked it from the README under the matrix section. Added current as of date for CSV in README to give a sense of the last update for future cleanups as the project evolves
• Fixed typo in TAKEOVER-4/-5/-6/-7 where DETECT-5 was labeled twice.
• Fixed typo in DETECT-1 where TAKEOVER-4’s hyperlink pointed to TAKEOVER-5.
• Fixed attack and defense technique hyperlinks on the main page to point to the correct locations (previously referenced a non-applicable template path).

Notes for reviewers

• The CSV is intended to be a maintainble source of truth for the matrix, with the README table serving as a readable snapshot.
• Technique associations were validated by cross-checking linked technique pages; when one side referenced the other, mappings were made consistent in both directions.

Happy to split this PR up if you prefer one for updated documentation and another for the CSV file addition idea. I packaged this as a single PR as this reflects the corrected mappings in one review.