0.5.18

• Update documentation: as of Rust 1.45 proc-macro-hack is superseded by native support for #[proc_macro] in expression position. Only continue using this crate if you care about supporting compilers between 1.31 and 1.45. https://blog.rust-lang.org/2020/07/16/Rust-1.45.0.html#stabilizing-function-like-procedural-macros-in-expressions-patterns-and-statements