fix: check content-type before applying spa patch (closes #597)

Jacky Zhao

2023-11-17 3f0be7fbe470500a57c457ad1d1c039175330697

 quartz/plugins/emitters/index.ts

@@ -7,3 +7,4 @@
export { Static } from "./static"
export { ComponentResources } from "./componentResources"
export { NotFoundPage } from "./404"
export { CNAME } from "./cname"