Add metadata for signals crate

packages/signals/Cargo.toml

@@ -3,6 +3,12 @@ name = "dioxus-signals"
 authors = ["Jonathan Kelley"]
 version = "0.4.3"
 edition = "2018"
+description = "Signals for Dioxus"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/DioxusLabs/dioxus/"
+homepage = "https://dioxuslabs.com"
+keywords = ["dom", "ui", "gui", "react", "wasm"]
+rust-version = "1.60.0"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html