Correcting command example validator exit
## Issue Addressed
None
## Proposed Changes
Using correct flag in example for exiting validator.
## Additional Info
None
@@ -42,7 +42,7 @@ The exit phrase is the following:
Below is an example for initiating a voluntary exit on the Pyrmont testnet.
```
-$ lighthouse --network pyrmont account validator exit --keystore /path/to/keystore --beacon-nodes http://localhost:5052
+$ lighthouse --network pyrmont account validator exit --keystore /path/to/keystore --beacon-node http://localhost:5052
Running account manager for pyrmont network
validator-dir path: ~/.lighthouse/pyrmont/validators
