This job runs on the 0th, 6th, 12th, 18th hour of the day e.g. midnight, 6am, midday 6pm.
To run it on the hour, every hour, just change the value to /1
Created a GITBOOK_TOKEN which lives in my 'secrets' section of github and was generated from the developer settings under my profile. It must be prefixed with secrets. in the action. It doesn't work if you just try and use GITBOOK_TOKEN or whatever you decide to call your secret.