[PATCH] doc: usage: Update the extension command title

[Bin Meng]

Update the extension command title for consistency with other commands.

Signed-off-by: Bin Meng <bmeng.cn at gmail.com>
---

 doc/usage/extension.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/doc/usage/extension.rst b/doc/usage/extension.rst
index 2b88398b18..6366cf56e7 100644
--- a/doc/usage/extension.rst
+++ b/doc/usage/extension.rst
@@ -1,8 +1,8 @@
 .. SPDX-License-Identifier: GPL-2.0+
 .. Copyright 2021, Kory Maincent <kory.maincent at bootlin.com>
 
-U-Boot extension board usage (CONFIG_EXTENSION)
-===============================================
+extension command
+=================
 
 Synopsis
 --------
-- 
2.25.1