update docs

Author: GrantBirki

docs/custom-deployment-messages.md

@@ -27,6 +27,8 @@ If a markdown file exists at the designated path, it will be used and rendered w
 - `parsed_params` - A string representation of the parsed deployment parameters (String)
 - `deployment_end_time` - The time the deployment ended - this value is not _exact_ but it is very close (String) [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) UTC format
 - `logs` - The URL to the logs of the deployment (String)
+- `commit_verified` - Whether or not the commit was verified (Boolean)
+- `total_seconds` - The total number of seconds the deployment took to complete (String of a number)
 
 If you wish to see a live example of how this works, and how to use the variables, you can check out this [example](https://github.com/github/branch-deploy/blob/691e5df06b952d1f22c2fee49f97e33a8a8c64db/__tests__/templates/test_deployment_message.md) which is used in this repo's unit tests and is self-documenting.