Documentation/faq: fix typo in flag names
### Configuration
-#### What is the difference between advertise-urls and listen-urls?
+#### What is the difference between listen-<client,peer>-urls, advertise-client-urls or initial-advertise-peer-urls?
-`listen-urls` specifies the local addresses etcd server binds to for accepting incoming connections. To listen on a port for all interfaces, specify `0.0.0.0` as the listen IP address.
+`listen-client-urls` and `listen-peer-urls` specify the local addresses etcd server binds to for accepting incoming connections. To listen on a port for all interfaces, specify `0.0.0.0` as the listen IP address.
-`advertise-urls` specifies the addresses etcd clients or other etcd members should use to contact the etcd server. The advertise addresses must be reachable from the remote machines. Do not advertise addresses like `localhost` or `0.0.0.0` for a production setup since these addresses are unreachable from remote machines.
+`advertise-client-urls` and `initial-advertise-peer-urls` specify the addresses etcd clients or other etcd members should use to contact the etcd server. The advertise addresses must be reachable from the remote machines. Do not advertise addresses like `localhost` or `0.0.0.0` for a production setup since these addresses are unreachable from remote machines.
#### Why doesn't changing `--listen-peer-urls` or `--initial-advertise-peer-urls` update the advertised peer URLs in `etcdctl member list`?
