PROCESS CHANGE: add new ready-to-work and not-ready-to-work labels

## Expected Benefits
By adding ready-to-work and not-ready-to-work labels to issues, contributors will have a much easier time finding issues to work on. We currently are marking issues "ready to work" in github projects, but not every issue is a part of a project and not every contributor will look at the projects to see if it is ready to work.

## Expected Costs
This will incur a small cost on the maintainers of repos as it will be another label to add to issues during the triage process. There is also a chance that the labels could get out of sync with the github projects (unless we found/made a prow plugin to automatically keep those in sync).

## Timeframe
Adding the labels can be done very quickly, and then the roll out of actually using the labels in individual repos will be up to the maintainers of each repo. Finding/creating a prow plugin to keep labels in sync with the github projects would take longer, but even if we want to pursue that path I don't think it would be a blocker to rolling out the new labels.

I am willing to add any necessary labels, and pursue the prow plugin path if needed.