Fixes: e8eee8d3 ("docs: Move microvm.rst into the system manual")

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20211012151447.4147923-1-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>