Lost the image for SGX-setup readme

[Michael-M-Zhang]

No picture shown in this readme file, looks like the image is lost https://github.com/intel/workload-services-framework/blob/main/doc/image/sgx-memory.png, I recall that I have added the picture in the original file [https://github.com/intel/workload-services-framework/blob/main/doc/setup-gramine-sgx.md].