tc/taprio: add a size table to the examples from the man page

tc/taprio: add a size table to the examples from the man page

Since kernel commit a3d91b2c6f6b ("net/sched: taprio: warn about missing
size table"), the kernel emits a warning netlink extack if the user
doesn't specify a stab. We want the user be aware of the fact that the
L1 overhead is determined by taprio exactly based on the overhead of the
stab, so we want to encourage users to add a size table to the Qdisc.
Teach them how.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>