readme: explain that step 3 is performed by Peter and Adrian

Author: maelvls

README.md

@@ -153,6 +153,9 @@ The chart will be mirrored to:
 
 ### Step 3: Release the Helm Chart "jetstack-secure"
 
+This step is performed by Peter Fiddes and Adrian Lai separately from the main
+release process.
+
 The [jetstack-agent](deploy/charts/jetstack-agent/README.md) chart has a different version number to the agent.
 This is because the first version of *this* chart was given version `0.1.0`,
 while the app version at the time was `0.1.38`.
@@ -168,6 +171,10 @@ This chart is for [Jetstack Secure](https://platform.jetstack.io/documentation/i
       Use a `v` prefix, to match the Docker image tag.
    1. Increment the `image.tag` value in [values.yaml](deploy/charts/jetstack-agent/values.yaml).
       Use a `v` prefix, to match the Docker image tag.
+   1. Update the Helm unit test snapshots:
+       ```sh
+       helm unittest ./deploy/charts/jetstack-agent --update-snapshot
+       ```
 1. Create a pull request and wait for it to be approved.
 1. Merge the branch
 1. Push a tag, using the format: `chart-vX.Y.Z`.