docs: fix code block close tag (#239)

README.md

@@ -61,7 +61,7 @@ And run `webpack`:
 
 ```console
 $ npx wp
-...
+```
 
 With the default options, the example above will create a `manifest.json` file in the output directory for the build. The manfist file will contain a map of source filenames to the corresponding build output file. e.g.