message: feat: Expose config's site values
  cobalt now exposes
  `site.name`
  `site.description`
  `site.base_url`
  The latter can be used to make correct paths, for example `{{site.base_url}}/{{post.path}}`.
  Fixes
diff: @@ -52,6 +52,15 @@ impl SiteBuilder {
  });
  let mut attributes = liquid::Object::new();
  + if let Some(ref name) = name {
  + attributes.insert("name".to_owned(), liquid::Value::str(name));
  + }
  + if let Some(ref description) = description {
  + attributes.insert("description".to_owned(), liquid::Value::str(description));
  + }
  + if let Some(ref base_url) = base_url {
  + attributes.insert("base_url".to_owned(), liquid::Value::str(base_url));
  + }
  let mut data = liquid::Object::new();
  insert_data_dir(&mut data, &root.join(data_dir))?;
  if !data.is_empty() {
  