Dead link to custom control output templates

[vil02]

The link in the line:

steampipe-action-setup/README.md

Line 142 in 8851809

Run local controls and post failure on slack with a [custom control output template](https://steampipe.io/docs/develop/writing-control-output-templates).

is dead.

I am unable to find the correct one.

[pskrbasu]

@vil02 Thank you for bringing it to our attention. We will get it sorted! 🚀