Finds all github_repository references in ./*.tf code not in Terraform state and imports them
Requires the github_repository identifiers in *.tf code to match the GitHub repo name, which does not work with repos which have dots in them eg. '.github'. Those rare exceptions must be imported manually.
If \$TERRAFORM_PRINT_ONLY is set to any value, prints the commands to stdout to collect so you can check, collect into a text file or pipe to a shell or further manipulate, ignore errors etc.