docs: excluded parent dir's metadata can't restore. (#6062)

docs: if parent dir is not extracted, we do not have its metadata

docs/usage/extract.rst.inc

@@ -118,4 +118,8 @@ pass over the archive metadata.
 .. note::
 
     Currently, extract always writes into the current working directory ("."),
-    so make sure you ``cd`` to the right place before calling ``borg extract``.
+    so make sure you ``cd`` to the right place before calling ``borg extract``.
+
+    When parent directories are not extracted (because of using file/directory selection
+    or any other reason), borg can not restore parent directories' metadata, e.g. owner,
+    group, permission, etc.

docs/usage/help.rst.inc

@@ -167,6 +167,12 @@ Examples::
     a directory, it won't recurse into it and won't discover any potential matches for
     include rules below that directory.
 
+    .. note::
+
+        It's possible that a sub-directory/file is matched while parent directories are not.
+        In that case, parent directories are not backed up thus their user, group, permission,
+        etc. can not be restored.
+
     Note that the default pattern style for ``--pattern`` and ``--patterns-from`` is
     shell style (`sh:`), so those patterns behave similar to rsync include/exclude
     patterns. The pattern style can be set via the `P` prefix.