[#1268] Remove applied wiki migration patch (#1277)

Remove the wiki migration patch introduced in #1268, which has been
applied to the wiki in commit
`80e637cc8b073857e2c8be1d31e830c139edf6d4`.

Update the documentation README to record the completed migration and
remove the obsolete publication instructions. Preserve the migration
inventory and guidance for maintaining the wiki relocation notices.

Validation: `git apply --reverse --check` passed against wiki HEAD
`80e637c`, confirming that the patch is applied. `git diff --check`
passed, and no references to the deleted patch remain. No build was run
for this documentation cleanup.

Follow-up to #1268.