Add material on different type of memories

[lucaparisi91]

• managed memory
• unified memory ( with page migration)
• coarse grained / fine grained memory ( AMD only concept ? )

Pinned memory is currently covered on the advance topics lesson.
Might be a good fit for #24 or #20 .

[lucaparisi91]

Managed memory is not an OpenMP concept, unlike unified memory, so unsure if including it. Managed memory just tells the compiler to do allocations differently, but do OpenMP it is the same as managed memory ( no #pragma omp requires managed_memory in the standard )

[lucaparisi91]

I left out the coarse grained/ fine grained material out of it. And material has been added to the slides.