Planetscale recipe

### What do you want and why?

As a developer, I would like to be able to easily integrate planetscale db, blitz, and render.com

### Possible implementation(s)

1. modify `blitz install render` to support a planetscale-compatible YAML
2. make `blitz install render-planetscaledb` or similar; basically a new recipe
3. no recipe, just update [deploy to render docs](https://blitzjs.com/docs/deploy-render) to include YAML that works with planetscale db.