README: add NXEngine port #467

Job	Run time
build-image / build-image-musl	32m 42s
build-image / build-sdk-uclibc-static	16m 59s
build-image / build-sdk-musl-static	17m 25s
build-image / build-image-uclibc	32m 17s
docker-musl-static	2m 32s
docker-musl	3m 40s
docker-uclibc-static	2m 2s
docker-uclibc	2m 7s
MiyooCFW	1m 43s
gmenu2x / GMenu2X for MiyooCFW (uClibc)	1m 11s
daemon / daemon for MiyooCFW (musl)	29s
daemon / daemon for MiyooCFW (uClibc)	30s
gmenu2x / GMenu2X for MiyooCFW (musl)	1m 14s
kernel / kernel for MiyooCFW (uClibc)	1m 27s
logo / boot logos for MiyooCFW (uClibc)	36s
logo / boot logos for MiyooCFW (musl)	33s
miyooctl / miyooctl for MiyooCFW (uClibc)	34s
miyooctl / miyooctl for MiyooCFW (musl)	27s
uboot / U-Boot for MiyooCFW (uClibc)	1m 32s
uboot / U-Boot for MiyooCFW (musl)	1m 28s
MiyooCFW (submodules)	2m 4s
Artifacts cleanup	8s
	2h 3m 40s

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