Add IDEF0 diagrams: A0 (NN model compilation) (#30)

Add IDEF0 diagrams: A0 (NN model compilation) (#30)

* Add IDEF0 diagrams: A0 (NN model compilation)

This commit adds the A0 diagram, used IDEF0 notation to describe the
first level of decomposition of nncc functionality: NN model compilation

Signed-off-by: Sergey Vostokov <s.vostokov@samsung.com>
* Update IDEF0 A0

Add name of root node as A0
Fix typo TRA -> TRE

Signed-off-by: Sergey Vostokov <s.vostokov@samsung.com>
* Update outcome of A0 diagram to Target binaries

The main function outcome was updated as Target binaries instead of
3 types of outcomes: ARM CPU executable/ARM GPU shaders/NPU executable

Signed-off-by: Sergey Vostokov <s.vostokov@samsung.com>