remove unnecessary Option in documentation [ci skip]
//! #[structopt(name = "make-cookie")]
//! struct MakeCookie {
//! #[structopt(name = "supervisor", default_value = "Puck")]
-//! supervising_faerie: Option<String>,
+//! supervising_faerie: String,
//! #[structopt(name = "tree")]
//! /// The faerie tree this cookie is being made in.
//! tree: Option<String>,
