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

Jacky Zhao

2023-11-17 3f0be7fbe470500a57c457ad1d1c039175330697

 quartz/processors/filter.ts

@@ -1,5 +1,5 @@
import { BuildCtx } from "../ctx"
import { PerfTimer } from "../perf"
import { BuildCtx } from "../util/ctx"
import { PerfTimer } from "../util/perf"
import { ProcessedContent } from "../plugins/vfile"

export function filterContent(ctx: BuildCtx, content: ProcessedContent[]): ProcessedContent[] {