Why not use your knowledge of these exposed secrets for good? You know which repo they're coming from, it'd be super simple to let the owner know rather than potentially costing them time and money.
It also seems as though the only use of this site is to capitalise on other people's mistakes? It looks like you're just handing over leaked data to people who will definitely abuse it, which seems to go against your core business of preventing data leaks?
Well, you don't need to send an email necessarily, a GitHub issue with a guide on how to include sensitive data in a public repo would probably suffice.
This isn't awareness though. This is like telling a specific set of people about all the houses near by that have their front door key under the mat. You only become aware of the issue when it is too late.
It also seems as though the only use of this site is to capitalise on other people's mistakes? It looks like you're just handing over leaked data to people who will definitely abuse it, which seems to go against your core business of preventing data leaks?