feat: make og images an emitter to properly await image generation (#1826)

* checkpoint

* make emitters async generators

* fix

* custom font spec

* replace spinner, use disk cache for fonts

* use readline instead

* make og images look nice

quartz/plugins/emitters/helpers.ts

@@ -2,12 +2,13 @@ import path from "path"
 import fs from "fs"
 import { BuildCtx } from "../../util/ctx"
 import { FilePath, FullSlug, joinSegments } from "../../util/path"
+import { Readable } from "stream"
 
 type WriteOptions = {
   ctx: BuildCtx
   slug: FullSlug
   ext: `.${string}` | ""
-  content: string | Buffer
+  content: string | Buffer | Readable
 }
 
 export const write = async ({ ctx, slug, ext, content }: WriteOptions): Promise<FilePath> => {