add metafile flag (#22349)

Author: emily-shen

src/content/docs/workers/wrangler/commands.mdx

@@ -348,6 +348,8 @@ None of the options for this command are required. Also, many can be set in your
   - If you change your environment variables or bindings in the Cloudflare dashboard, Wrangler will override them the next time you deploy. If you want to disable this behaviour set `keep-vars` to `true`.
 - `--dispatch-namespace` <Type text="string" /> <MetaInfo text="optional" />
   - Specify the [Workers for Platforms dispatch namespace](/cloudflare-for-platforms/workers-for-platforms/get-started/configuration/#2-create-a-dispatch-namespace) to upload this Worker to.
+- `--metafile` <Type text="string" /> <MetaInfo text="optional" />
+  - Specify a file to write the build metadata from esbuild to. If flag is used without a path string, this defaults to `bundle-meta.json` inside the directory specified by `--outdir`. This can be useful for understanding the bundle size.
 
 <Render file="wrangler-commands/global-flags" product="workers" />
 
@@ -1199,6 +1201,8 @@ wrangler pages functions build [<DIRECTORY>] [OPTIONS]
   - Date to use for compatibility checks.
 - `--compatibility-flags` <Type text="string[]" /> <MetaInfo text="optional" />
   - Flags to use for compatibility checks.
+- `--metafile` <Type text="string" /> <MetaInfo text="optional" />
+  - Specify a file to write the build metadata from esbuild to. If flag is used without a path string, this defaults to `bundle-meta.json` inside the directory specified by `--outdir`. This can be useful for understanding the bundle size.
 
 <Render file="wrangler-commands/global-flags" product="workers" />