added license, author, metadata

crates/proton-sdk/Cargo.toml

@@ -5,7 +5,13 @@ version.workspace = true
 edition.workspace = true
 license.workspace = true
 repository.workspace = true
+homepage.workspace = true
+authors.workspace = true
+keywords.workspace = true
+categories.workspace = true
 rust-version.workspace = true
+readme = "../../README.md"
+documentation = "https://docs.rs/proton-sdk"
 
 [dependencies]
 tokio.workspace = true