//! # Parameters (syntax side)
//!
//! The per-parameter lens contract ([`VcardParamLens`](lens::VcardParamLens))
//! and one hand-written module per RFC 6350 parameter, tying a wire name to
//! its decoded shape.
//!
//! The markers are the type-level keys for
//! [`VcardLine::param`](crate::tree::line::VcardLine::param). The raw
//! [`VcardParamNode`](node::VcardParamNode) they read and write is defined
//! alongside.