qapi/char: Supply missing member documentation

Since we neglect to document several members of ChardevBackendKind,
their description in the QEMU QMP Reference manual is "Not
documented".  Fix that, and improve the existing member documentation.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240911112545.2248881-2-armbru@redhat.com>

qapi/char.json

@@ -434,37 +434,49 @@
 ##
 # @ChardevBackendKind:
 #
-# @pipe: Since 1.5
+# @file: regular files
 #
-# @udp: Since 1.5
+# @serial: serial host device
 #
-# @mux: Since 1.5
+# @parallel: parallel host device
 #
-# @msmouse: Since 1.5
+# @pipe: pipes (since 1.5)
 #
-# @wctablet: Since 2.9
+# @socket: stream socket
 #
-# @braille: Since 1.5
+# @udp: datagram socket (since 1.5)
 #
-# @testdev: Since 2.2
+# @pty: pseudo-terminal
 #
-# @stdio: Since 1.5
+# @null: provides no input, throws away output
 #
-# @console: Since 1.5
+# @mux: (since 1.5)
 #
-# @spicevmc: Since 1.5
+# @msmouse: emulated Microsoft serial mouse (since 1.5)
 #
-# @spiceport: Since 1.5
+# @wctablet: emulated Wacom Penpartner serial tablet (since 2.9)
 #
-# @qemu-vdagent: Since 6.1
+# @braille: Baum Braille device (since 1.5)
 #
-# @dbus: Since 7.0
+# @testdev: device for test-suite control (since 2.2)
 #
-# @vc: v1.5
+# @stdio: standard I/O (since 1.5)
 #
-# @ringbuf: Since 1.6
+# @console: Windows console (since 1.5)
 #
-# @memory: Since 1.5
+# @spicevmc: spice vm channel (since 1.5)
+#
+# @spiceport: Spice port channel (since 1.5)
+#
+# @qemu-vdagent: Spice vdagent (since 6.1)
+#
+# @dbus: D-Bus channel (since 7.0)
+#
+# @vc: virtual console (since 1.5)
+#
+# @ringbuf: memory ring buffer (since 1.6)
+#
+# @memory: synonym for @ringbuf (since 1.5)
 #
 # Features:
 #

qapi/pragma.json

@@ -46,7 +46,6 @@
         'BlockdevSnapshotSyncWrapper',
         'BlockdevSnapshotWrapper',
         'BlockdevVmdkAdapterType',
-        'ChardevBackendKind',
         'CxlCorErrorType',
         'DisplayProtocol',
         'DriveBackupWrapper',