Merge pull request #33 from kornelski/patch-1

Add crates-io category
diff --git a/Cargo.toml b/Cargo.toml
index 532041e..af5b59b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,6 +7,7 @@
 description = "derive(Error)"
 repository = "https://github.com/dtolnay/thiserror"
 documentation = "https://docs.rs/thiserror"
+categories = ["rust-patterns"]
 readme = "README.md"
 
 [dependencies]