M8: the redaction README says a name a form without resources draws stays

The Consumers review of 64dfe1fd4. The README said a surviving form loses
the resource entries for removed XObjects its own content does not draw.
It also keeps those a form without resources of its own, drawn through
them, still draws, and since this PR a redacted page keeps them the same
way.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY

crates/redact/README.md

@@ -148,8 +148,10 @@ used by surviving pages or forms are kept.
 A redacted page that inherits `/Resources` from the page tree gets them pinned (by reference;
 a direct inherited dictionary is made one shared object first) before it is rewritten. The parent's
 `/Resources` is then retired unless another page still inherits it, so it cannot keep a removed
-XObject reachable. Surviving form XObjects lose the resource entries for removed XObjects their own
-content doesn't draw, for the same reason. Pages that aren't redacted are left untouched.
+XObject reachable. Surviving form XObjects lose the resource entries for removed XObjects that
+neither their own content nor a form without resources of its own drawn through them still draws,
+for the same reason, and a redacted page keeps a name under that rule too. Pages that aren't
+redacted are left untouched.
 
 ## Remove hidden information / Sanitize