fix: frontmatter coercion (empty string is falsy)

Jacky Zhao

2023-12-09 2c69b0c97d40f76363d20478cb799ce4b7518e56

 quartz/util/ctx.ts

@@ -7,6 +7,8 @@
  output: string
  serve: boolean
  port: number
  wsPort: number
  remoteDevHost?: string
  concurrency?: number
}