doc: Add a description for bootmeth_sandbox
Add documentation for the sandbox bootmeth.
Fix up the compatible string to drop the 'extlinux' part, which is not
relevant to this bootmeth.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
diff --git a/doc/develop/bootstd/index.rst b/doc/develop/bootstd/index.rst
index 69fd3c2..2c5d2d3 100644
--- a/doc/develop/bootstd/index.rst
+++ b/doc/develop/bootstd/index.rst
@@ -11,3 +11,4 @@
pxelinux
qfw
cros
+ sandbox