Clarify the readme version
diff --git a/Cargo.toml b/Cargo.toml
index 7eae558..d284851 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "syn"
-version = "0.10.3" # don't forget to update version in readme
+version = "0.10.3" # don't forget to update version in readme for breaking changes
 authors = ["David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Nom parser for Rust items"