Remove both the ELDK and emdebian links as they are broken, and add a
link to the kernel.org toolchains which we use in CI.
Signed-off-by: Tom Rini <trini@konsulko.com>
Convert plain text documentation to reStructuredText format and add
it to Sphinx TOC tree. No essential content change.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>