Move avatar to directory the workflow can reach

Author: LenNerd42

_config.yml

@@ -95,7 +95,7 @@ theme_mode: # [light | dark]
 cdn:
 
 # the avatar on sidebar, support local or CORS resources
-avatar: assets/lib/avatar.png
+avatar: assets/img/avatar.png
 
 # The URL of the site-wide social preview image used in SEO `og:image` meta tag.
 # It can be overridden by a customized `page.image` in front matter.