qmp-commands: move 'screendump' doc to schema

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

docs/qmp-commands.txt

@@ -72,20 +72,6 @@ Example:
 
 Note: The "force" argument defaults to false.
 
-screendump
-----------
-
-Save screen into PPM image.
-
-Arguments:
-
-- "filename": file path (json-string)
-
-Example:
-
--> { "execute": "screendump", "arguments": { "filename": "/tmp/image" } }
-<- { "return": {} }
-
 device_add
 ----------
 

qapi-schema.json

@@ -4608,6 +4608,13 @@
 # Returns: Nothing on success
 #
 # Since: 0.14.0
+#
+# Example:
+#
+# -> { "execute": "screendump",
+#      "arguments": { "filename": "/tmp/image" } }
+# <- { "return": {} }
+#
 ##
 { 'command': 'screendump', 'data': {'filename': 'str'} }