Merge pull request #11 from agntcy/docs/a2a-rustdoc

docs: add crate rustdoc for agntcy-a2a

Author: muscariello

a2a/src/lib.rs

@@ -1,5 +1,7 @@
 // Copyright AGNTCY Contributors (https://github.com/agntcy)
 // SPDX-License-Identifier: Apache-2.0
+#![doc = include_str!("../README.md")]
+
 pub mod agent_card;
 pub mod errors;
 pub mod event;