Add log line to debg workspace-in-sidecar example

Prior to this commit the workspace-in-sidecar example didn't print anything before creating a fifo file in its first Step. When the example fails we are missing information here that would be useful to debug whether the Step ever started or is blocking on that `mkfifo` call.

This commit adds the log line we need to debug whether the Step ever starts.

examples/v1beta1/taskruns/alpha/workspace-in-sidecar.yaml

@@ -24,6 +24,7 @@ spec:
           cpu: "100m"
       script: |
         #!/usr/bin/env ash
+        echo "Creating FIFO..."
         mkfifo "$(workspaces.signals.path)/channel"
         echo "Greeting sidecar..."
         echo "hello there" > "$(workspaces.signals.path)/channel"

examples/v1beta1/taskruns/workspace-in-sidecar.yaml

@@ -25,6 +25,7 @@ spec:
           cpu: "100m"
       script: |
         #!/usr/bin/env ash
+        echo "Creating FIFO..."
         mkfifo "$(workspaces.signals.path)/channel"
         echo "Greeting sidecar..."
         echo "hello there" > "$(workspaces.signals.path)/channel"