Add link to the blog post (and a second guide link) to the README #202

Job	Run time
build artifacts [x64-linux]	1s
build and check docs [x64-windows]	1s
build mdbook guide [x64-windows]	1s
build openhcl [aarch64-linux]	1s
build openhcl [x64-linux]	1s
clippy [windows], unit tests [x64-windows]	1s
clippy [linux, macos], unit tests [x64-linux]	1s
clippy [linux-musl, misc nostd], unit tests [x64-linux-musl]	1s
test flowey local backend	1s
build and check docs [x64-linux]	1s
xtask fmt (linux)	1s
build artifacts (not for VMM tests) [aarch64-windows]	1s
build artifacts (for VMM tests) [aarch64-windows]	39s
build artifacts (not for VMM tests) [x64-windows]	1s
build artifacts (for VMM tests) [x64-windows]	39s
build artifacts [aarch64-linux]	1s
run vmm-tests [x64-windows-amd]	1s
run vmm-tests [x64-windows-intel]	1s
run vmm-tests [x64-linux]	1s
xtask fmt (windows)	1s
openvmm checkin gates	1s
	1m 37s

Provide feedback