Provided example base url

Because otherwise RSS feeds are broken

_config.yml

@@ -1,6 +1,7 @@
 # Site settings
 title: Freelancer
 email: your-email@domain.com
+url: https://example.github.io
 description: "Write an awesome description for your new site here. You can edit this line in _config.yml. It will appear in your document head meta (for Google search results) and in your feed.xml site description."
 
 # Color settings (hex-codes without the leading hash-tag)