update USERS.md: add link to Trip.com's post
update USERS.md: add link to Trip.com's post

Signed-off-by: ArthurChiao <16a56a00a836623a07eccc04d896898d9695bb9c@hotmail.com>

michi-covalent/cilium,tklauser/cilium,tklauser/cilium,cilium/cilium,michi-covalent/cilium,tklauser/cilium,tgraf/cilium,cilium/cilium,michi-covalent/cilium,cilium/cilium,tgraf/cilium,cilium/cilium,tgraf/cilium,tklauser/cilium,cilium/cilium,cilium-team/cilium,tgraf/cilium,michi-covalent/cilium,cilium-team/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium