Add repository and description fields to the Cargo.toml files

Cargo.toml

@@ -3,6 +3,8 @@ name = "sigma-compiler"
 version = "0.1.0-rc1"
 edition = "2021"
 license = "MIT"
+repository = "https://git-crysp.uwaterloo.ca/SigmaProtocol/sigma-compiler"
+description = "Crate for automatically generating code for sigma zero-knowledge proof protocols of more complex statements than are supported by the sigma-proofs crate.  The statements given to this crate are compiled into statements about linear combinations of points, and transformed into the sigma-proofs API."
 
 [dependencies]
 group = "0.13"

sigma-compiler-core/Cargo.toml

@@ -3,6 +3,8 @@ name = "sigma-compiler-core"
 version = "0.1.0-rc1"
 edition = "2021"
 license = "MIT"
+repository = "https://git-crysp.uwaterloo.ca/SigmaProtocol/sigma-compiler"
+description = "Core functionality for the macros in the sigma-compiler crate"
 
 [dependencies]
 syn = { version = "2.0", features = ["extra-traits", "visit", "visit-mut", "full"] }

sigma-compiler-derive/Cargo.toml

@@ -3,6 +3,8 @@ name = "sigma-compiler-derive"
 version = "0.1.0-rc1"
 edition = "2021"
 license = "MIT"
+repository = "https://git-crysp.uwaterloo.ca/SigmaProtocol/sigma-compiler"
+description = "Derive macros for the sigma-compiler crate"
 
 [lib]
 proc-macro = true