docs: fix typo in `authoring content.md` (#408)

Ben Schlegel

2023-08-24 9d2340e90b55fb9480e0901bc7360f3d72e688da

 quartz/cfg.ts

@@ -1,6 +1,6 @@
import { QuartzComponent } from "./components/types"
import { PluginTypes } from "./plugins/types"
import { Theme } from "./theme"
import { Theme } from "./util/theme"

export type Analytics =
  | null