ShellPkg: Remove unnecessary Readme.txt

The Readme.txt contains instructions about how to integrate Shell
into Nt32. Actually Nt32 already contains a macro USE_OLD_SHELL to
choose OLD or NEW Shell.

So remove this txt file.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>
(cherry picked from commit 752234768eee79c3e9b32b9a2d134148ecaa635a)
1 file changed