Update description in Cargo.toml

Author: wooorm

Cargo.toml

@@ -4,7 +4,7 @@ version = "1.0.0-alpha.1"
 authors = ["Titus Wormer <[email protected]>"]
 edition = "2018"
 rust-version = "1.56"
-description = "small commonmark compliant markdown parser with positional info and concrete tokens"
+description = "CommonMark compliant markdown parser in Rust with ASTs and extensions"
 homepage = "https://github.com/wooorm/markdown-rs"
 repository = "https://github.com/wooorm/markdown-rs"
 license = "MIT"