docs: state the site-configuration deviation instead of claiming it is gone

docs/wiki/foundations/Documentation-Convention.md

@@ -28,7 +28,9 @@ folder this playbook publishes from. Of the seventeen public repositories in the
 use `docs/wiki`; `architests`, `value-objects` and `purview-dev.github.io` publish from `docs`, and
 `pm-skills` publishes no documentation folder at all, documenting itself through its skills. What the
 rule requires is the part those repositories share: the documentation lives with the code it describes,
-as Markdown, with its navigation in the folder beside it. The folder name is the only part that varies.
+as Markdown, with its navigation in the folder beside it. The folder name is the part that varies. Some
+repositories still carry a site configuration file from before the portal read Markdown directly; it is
+harmless, the portal ignores it, and this playbook does not ship one.
 [Cross-Repository Harvest](../governance/Cross-Repository-Harvest.md) records the deviations by name.
 
 ## Why

docs/wiki/governance/Cross-Repository-Harvest.md

@@ -76,10 +76,10 @@ publish from `docs`, and `pm-skills` publishes no documentation folder at all, d
 through its eighteen skills.
 
 That is not seventeen repositories getting a rule wrong; it is one repository's shape written down as if
-it were universal. What the rule actually requires is that the documentation lives with the code — the
-folder name is the part that varies, and nothing else does, because no repository carries a site
-configuration any more (`astroc4` publishes `docs/wiki` and nothing beside it). The convention page now
-says so, and names each deviation rather than pretending the rule was followed.
+it were universal. What the rule actually requires is that the documentation lives with the code, as
+Markdown the portal can read: the folder name is the part that varies, and `astroc4` publishes
+`docs/wiki` with no site configuration beside it, which is the shape the rule now states. The convention
+page now says so, and names each deviation rather than pretending the rule was followed.
 
 ## How it is enforced