add homepage & repo manifest fields

Cargo.toml

@@ -3,6 +3,8 @@ name = "ark-circom"
 version = "0.5.0-alpha"
 edition = "2018"
 description = "Arkworks bindings to Circom's R1CS, for Groth16 Proof and Witness generation in Rust"
+homepage = "https://arkworks.rs"
+repository = "https://github.com/arkworks-rs/circom-compat"
 license = "MIT OR Apache-2.0"
 
 [lib]