fix(values): Fix links to "Disagree, commit, and advocate".

The section used to be called "Disagree, commit, and disagree" and was renamed
in !3378. This broke links to this principle
throughout the handbook.

This change adds an explicit, stable anchor `#disagree-and-commit`, which is *not*
automatically derived from the heading's text. All references have been updated
to use the stable anchor.