qapi: BlockExportRemoveMode: move comments to TODO

@hide and @soft are potential additions which fits the TODO section
perfectly.

The main motivation is to avoid this whole block of comment entering
the wrong section in the python parser.

Signed-off-by: Victor Toso <victortoso@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-Id: <20220328140604.41484-2-victortoso@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/block-export.json

@@ -219,13 +219,13 @@
 #
 # @hard: Drop all connections immediately and remove export.
 #
-# Potential additional modes to be added in the future:
+# TODO: Potential additional modes to be added in the future:
 #
-# hide: Just hide export from new clients, leave existing connections as is.
-# Remove export after all clients are disconnected.
+#       hide: Just hide export from new clients, leave existing connections as is.
+#       Remove export after all clients are disconnected.
 #
-# soft: Hide export from new clients, answer with ESHUTDOWN for all further
-# requests from existing clients.
+#       soft: Hide export from new clients, answer with ESHUTDOWN for all further
+#       requests from existing clients.
 #
 # Since: 2.12
 ##