No online logos in Typst

Author: cwickham

docs/authoring/brand.qmd

@@ -166,7 +166,15 @@ logo:
   medium: logo.png
 ```
 
-You can specify a local file path, relative to the location of `_brand.yml`, or a URL (*is this true?*).
+You can specify a local file path, relative to the location of `_brand.yml`, or a URL that starts with `http://` or `https://`.
+
+::: {.callout-warning}
+
+## Limitation
+
+Logos specified as URLs are not currently supported in `format: typst`.
+
+::: 
 
 A single logo may not work well in all locations so **brand.yml** allows you to set three different logos: `small`, `medium` and `large`. For example: