Update keywords

Author: aramperes

nut-client/Cargo.toml

@@ -5,7 +5,7 @@ authors = ["Aram Peres <aram.peres@wavy.fm>"]
 edition = "2018"
 description = "Network UPS Tools (NUT) client library"
 categories = ["network-programming"]
-keywords = ["ups", "nut"]
+keywords = ["ups", "nut", "tokio", "async"]
 repository = "https://github.com/aramperes/nut-client-rs"
 documentation = "https://docs.rs/nut-client"
 readme = "../README.md"