no mention of ocptv output

[mimir-d]

By manual inspection of the code, I found

ocp-diag-autoval/src/autoval/lib/utils/autoval_output.py

Line 16 in 9180c63

import ocptv.output as tv

which points to ocptv output being generated. However, there's 2 issues with this:

1. the readme has no mention of this output
2. generally, ocptv compliant diags will output ocptv json on stdout; in this case, it's hardcoded to go to a file. There should be a flag to the runner to say "output ocptv json", and that this output is the one meant for machine consumption. For any other logging/output, there should be a message to explicitly say that anything other than ocptv output is not meant for machines, but only humans.