Use generic domain for community checkpoint sync example
## Proposed Changes
Use a generic domain for community checkpoint sync example to meet the concern raised in
@@ -45,7 +45,7 @@ as soon as forwards sync completes.
The Ethereum community provides various [public endpoints](https://eth-clients.github.io/checkpoint-sync-endpoints/) for you to choose from for your initial checkpoint state. Select one for your network and use it as the url for the `--checkpoint-sync-url` flag. e.g.
```
-lighthouse bn --checkpoint-sync-url https://beaconstate.info/ ...
+lighthouse bn --checkpoint-sync-url https://example.com/ ...
```
### Use Infura as a remote beacon node provider
