Add a page showing the logo with and without text.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

This video covers the basics in a short time, so add a link to it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

The list of u-boot talks on elinux.org is quite long, so let's highlight
the talks which are likely most relevant for newcomers.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Talks are a great way to learn about U-Boot and have been lost now that
the Denx Wiki has gone away.

These are stored at elinux.org so link to that .

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Sean Anderson <seanga2@gmail.com>