feat(showcase): add QHacks to site showcase (#9617)
feat(showcase): add QHacks to site showcase (#9617)

## Proposed Change

Submit [QHacks](https://qhacks.io) to the site showcase! 😄 

### How did you do this?

Add the QHacks information to `sites.yml`.

### Why are you choosing this approach?

Share our work with others and help promote Gatsby.

### Any open questions you want to ask code reviewers?

I added the `Hackathon` category because it didn't exist, to add it do I just include it as a category?

### List of changes:

  - Add QHacks information to the `sites.yml`

ChristopherBiscardi/gatsby,0x80/gatsby,ChristopherBiscardi/gatsby,gatsbyjs/gatsby,ChristopherBiscardi/gatsby,mingaldrichgan/gatsby,ChristopherBiscardi/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,0x80/gatsby,0x80/gatsby,gatsbyjs/gatsby,mingaldrichgan/gatsby,mingaldrichgan/gatsby,gatsbyjs/gatsby