[Command-Reference.md] Some errors in Command-Reference.md

[philo-micas]

Description

1、URL of FRR Command Reference is invalid.
This command displays the route-map that is configured for the IPv6 routing protocol. Refer the routing stack Quagga Command Reference or FRR Command Reference to know more about this command.

2、One command does not match display information in DHCP_RELAY

Steps to reproduce the issue

NA

Describe the results you received

NA

Describe the results you expected

NA

Additional information you deem important (e.g. issue happens only occasionally)

NA

Output of show version

NA

(paste your output here)