qapi: convert "Example" sections without titles

Use the no-option form of ".. qmp-example::" to convert any Examples
that do not have any form of caption or explanation whatsoever. Note
that in a few cases, example sections are split into two or more
separate example blocks. This is only done stylistically to create a
delineation between two or more logically independent examples.

See commit-3: "docs/qapidoc: create qmp-example directive", for a
              detailed explanation of this custom directive syntax.

See commit+3: "qapi: remove "Example" doc section" for a detailed
              explanation of why.

Note: an empty "TODO" line was added to announce-self to keep the
example from floating up into the body; this will be addressed more
rigorously in the new qapidoc generator.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-ID: <20240717021312.606116-7-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Markup fixed in one place]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/qapi/machine-target.json b/qapi/machine-target.json
index a8d9ec8..7edb876 100644
--- a/qapi/machine-target.json
+++ b/qapi/machine-target.json
@@ -475,7 +475,7 @@
 #
 # Since: 8.2
 #
-# Example:
+# .. qmp-example::
 #
 #     <- { "event": "CPU_POLARIZATION_CHANGE",
 #          "data": { "polarization": "horizontal" },