add a few more buildnotes in comments
add a few more buildnotes in comments

ujamjar/rumpuser-baremetal,rumpkernel-attic/rumprun-baremetal,ujamjar/rumpuser-baremetal,ujamjar/rumpuser-baremetal,rumpkernel-attic/rumprun-baremetal,rumpkernel-attic/rumprun-baremetal