feat: README example that demonstrates multiple search queries with 1 report

[zkoppert]

README example that demonstrates multiple search queries with 1 report

Use case: I want to be able to run different searches in different repositories and report on the metrics in a single markdown report
Use case: I want to be able to see both open and closed issues over a certain time period

This could look like feeding the action a list of SEARCH_QUERYs or a workflow file that ties together several json outputs to create a single markdown report.

[Okabe-Junya]

Hi!

I have created a workflow to accomplish this and inspected that it works well in a sandbox environment. I'd like to send a PR later.

During inspection in my sandbox repo, I accidentally attached several reference comments to the issue because I was collecting metrics from this repo. (This is how it appears from my environment.)

This is not ideal, so I made my sandbox repo private, but if it's no problem, I would like to make it public again. (It's certainly not malicious spam.)

I hope the PR will be merged.