Templates

super: The parent block’s content (inside {% block %} only).
partial: Renders _partials/<name> with the kwargs as top-level names; returns its return_value or the rendered string.
partial_cached: partial memoised on (name, key).
return_value: Sets the value the enclosing partial() returns. Prints nothing.
template_exists: Whether a template called name exists.
defer: A placeholder; template is rendered once per key with data after all pages.
arg: A shortcode argument by position index or by name, else default: shortcode | arg(index=0, default="").