### What this PR does / why we need it?
update pd disaggregation multi_node readme, update the environment check
command for A3, add tls check
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: v0.13.0
- vLLM main:
8be6432bda
Signed-off-by: liziyu <liziyu16@huawei.com>