FPGA Readme needs to add note about how to get FPGA after 2024.2 release

[bdmoore1]

Summary

The readme in the DirectPrograming/C++SYCL_FPGA/ says you need the base toolkit to use the FPGA samples. With the 2024.2 release targeted for June 24, FPGA bits will be removed from oneAPI toolkits so users will need an alternate method to install the FPGA bits. This method is still being defined by Thorsten Mueller and @erickoeck. Once it is defined, this README should be updated to point to the new method.

URLs

Include pointers to documents that are impacted.

The new method will be updated in https://jira.devtools.intel.com/browse/DOC-12388 once it is ready.