doc: update cargo manifests with keywords

embassy-macros/Cargo.toml

@@ -3,6 +3,13 @@ name = "embassy-macros"
 version = "0.1.0"
 edition = "2021"
 license = "MIT OR Apache-2.0"
+description = "macros for creating the entry point and tasks for embassy-executor"
+repository = "https://github.com/embassy-rs/embassy"
+categories = [
+    "embedded",
+    "no-std",
+    "asynchronous",
+]
 
 [dependencies]
 syn = { version = "1.0.76", features = ["full", "extra-traits"] }