Rename procedure link file to tofupilot.json

The file tofupilot link writes to bind a local procedure directory to the dashboard is now named after the product, so it is easier to recognize in your repo.

• Renamed the link file from procedure.json to tofupilot.json; re-run tofupilot link in previously linked directories after updating
• Improved error messages to reflect that procedure files can use any .yaml or .yml name, not only procedure.yaml
• Clarified the no-procedure-found error to list everything the CLI looks for in a directory