qapi: add some sections in docs

Add some more section titles to organize the documentation we're going
to generate.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <20170113144135.5150-10-marcandre.lureau@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

qapi-schema.json

@@ -20,6 +20,10 @@
 # QAPI introspection
 { 'include': 'qapi/introspect.json' }
 
+##
+# = QMP commands
+##
+
 ##
 # @qmp_capabilities:
 #

qapi/block-core.json

 # -*- Mode: Python -*-
-#
-# QAPI block core definitions (vm unrelated)
+
+##
+# == QAPI block core definitions (vm unrelated)
+##
 
 # QAPI common definitions
 { 'include': 'common.json' }

qapi/block.json

 # -*- Mode: Python -*-
-#
-# QAPI block definitions (vm related)
+
+##
+# = QAPI block definitions
+##
 
 # QAPI block core definitions
 { 'include': 'block-core.json' }
 
+##
+# == QAPI block definitions (vm unrelated)
+##
+
 ##
 # @BiosAtaTranslation:
 #

qapi/common.json

 # -*- Mode: Python -*-
-#
-# QAPI common definitions
+
+##
+# = QAPI common definitions
+##
 
 ##
 # @QapiErrorClass:

qapi/crypto.json

 # -*- Mode: Python -*-
 #
-# QAPI crypto definitions
+
+##
+# = QAPI crypto definitions
+##
 
 ##
 # @QCryptoTLSCredsEndpoint:

qapi/event.json

+# -*- Mode: Python -*-
+
+##
+# = Other events
+##
+
 ##
 # @SHUTDOWN:
 #

qapi/rocker.json

+##
+# = Rocker switch device
+##
+
 ##
 # @RockerSwitch:
 #

qapi/trace.json

@@ -5,6 +5,9 @@
 # This work is licensed under the terms of the GNU GPL, version 2 or later.
 # See the COPYING file in the top-level directory.
 
+##
+# = Tracing commands
+##
 
 ##
 # @TraceEventState: