docs: Asterisk first mention of Docker
docs: Asterisk first mention of Docker

Add an asterisk to the first mention of Docker in the limitations
document.

Signed-off-by: James O. D. Hunt <348fbaadfbada55ea105602bf5609e23ac1c4898@intel.com>

clearcontainers/runtime,clearcontainers/runtime,devimc/runtime,devimc/runtime,chavafg/runtime,chavafg/runtime