docs: use :kbd: role in sphinx docs

docs: use :kbd: role in sphinx docs

Sphinx supports the :kbd: role for notating keyboard input. They get
formatted as <kbd> HTML elements in the readthedocs theme we currently
use for Sphinx.

Besides the better visual formatting, it also helps with accessibility
as screen readers can announce the semantics of the <kbd> element to the
user.

Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Message-ID: <20250709-docs_rst_improvements-v2-1-cb5096ad0022@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-ID: <20250710104531.3099313-7-alex.bennee@linaro.org>