adding table to readme to better show repos, recipes, and runs

[vsoch]

This will close #62, adding the table to render:

• the repository name and link
• the most interesting workflow that uses urlchecker
• the link to a recent and successful run

@maelle take a look and let me know if this is what you had in mind!

Signed-off-by: vsoch vsochat@stanford.edu

[vsoch]

Closing in favor of https://github.com/urlstechie/urlchecker-action/pull/63