docs(readme): Be consistent in project description

This takes from `lib.rs` and spreads it around

Author: epage

Cargo.toml

@@ -97,7 +97,7 @@ lto = true
 [package]
 name = "annotate-snippets"
 version = "0.12.1"
-description = "Library for building code annotations"
+description = "Format diagnostic reports, including highlighting snippets of text"
 categories = []
 keywords = ["code", "analysis", "ascii", "errors", "debug"]
 repository.workspace = true

README.md

@@ -1,6 +1,6 @@
 # annotate-snippets
 
-`annotate-snippets` is a Rust library for annotation of programming code slices.
+> Format diagnostic reports, including highlighting snippets of text
 
 [![crates.io](https://img.shields.io/crates/v/annotate-snippets.svg)](https://crates.io/crates/annotate-snippets)
 [![documentation](https://img.shields.io/badge/docs-master-blue.svg)][Documentation]