Add README.md with installation instructions

README.md

@@ -0,0 +1,12 @@
+= INSTALLATION
+
+To install HOS to an EFI partition, follow these steps:
+
+1. copy build/hello/BOOTX64.EFI to /boot/efi/EFI/HOS.EFI (as root).
+2. Register EFI loader for HOS (one time only) with command:
+
+    efibootmgr -c -d /dev/nvme1n1p2 -l '\EFI\HOS.EFI' -L HOS
+
+3. Set boot order to desired boot order. Exact order will be system dependent. Example:
+
+    efibootmgr -o 2,0,6,5