doc: add interrupt high-level design doc

Transcode, review, and publish interrupt high-level design document.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

Author: dbkinder

doc/developer-guides/images/interrupt-image2.png

@@ -24,6 +24,7 @@ specific areas within the ACRN hypervisor system.
    virtio-console.rst
    uart-virtualization.rst
    ACPI-virt-hld.rst
+   interrupt-hld.rst
    APL_GVT-g-hld.rst
    GVT-G-porting.rst