EmbeddedPkg: convert Lauterbach README.txt to 7-bit safe Readme.md

EmbeddedPkg: convert Lauterbach README.txt to 7-bit safe Readme.md

This file contained what looked like windows 1250 encoded single
quotation marks. Convert them to regular 's. Rework the file to
markdown format and and rename it Readme.md while we're at it.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: "Kinney, Michael D" <michael.d.kinney@intel.com>
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com>