doc: man-page for panic command

Provide a man-page for the panic command.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

doc/usage/cmd/panic.rst

@@ -0,0 +1,33 @@
+.. SPDX-License-Identifier: GPL-2.0+:
+
+panic command
+=============
+
+Synopis
+-------
+
+::
+
+    panic [message]
+
+Description
+-----------
+
+Display a message and reset the board.
+
+message
+    text to be displayed
+
+Examples
+--------
+
+::
+
+    => panic 'Unrecoverable error'
+    Unrecoverable error
+    resetting ...
+
+Configuration
+-------------
+
+If CONFIG_PANIC_HANG=y, the user has to reset the board manually.

doc/usage/index.rst

@@ -65,6 +65,7 @@ Shell commands
    cmd/md
    cmd/mmc
    cmd/mtest
+   cmd/panic
    cmd/part
    cmd/pause
    cmd/pinmux