/// Returns the `Some` value or the provided default.
///
/// ```
/// use std::fmt::Error;
///
/// use oxiplate::prelude::*;
///
/// #[derive(Oxiplate)]
/// #[oxiplate_inline(html: r#"{{ value | default("Bar") }}"#)]
/// struct Data {
/// value: Option<&'static str>,
/// }
///
/// fn main() -> Result<(), Error> {
/// assert_eq!(Data { value: None }.render()?, "Bar");
/// Ok(())
/// }
/// ```