Update crate doc comment

graphql_client_codegen/src/lib.rs

@@ -2,9 +2,7 @@
 #![warn(rust_2018_idioms)]
 #![allow(clippy::option_option)]
 
-//! Crate for internal use by other graphql-client crates, for code generation.
-//!
-//! It is not meant to be used directly by users of the library.
+//! Crate for Rust code generation from a GraphQL query, schema, and options.
 
 use lazy_static::*;
 use proc_macro2::TokenStream;