[proptest-macro] [Fix] Manifest : add metadata required to publish, c…

…opied from core proptest crate (#469)

proptest-macro/Cargo.toml

@@ -1,7 +1,15 @@
 [package]
 name = "proptest-macro"
+description = "Procedural macros for the proptest crate"
 version = "0.1.0"
+authors = ["The Proptest Developers"]
 edition = "2021"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/proptest-rs/proptest"
+homepage = "https://proptest-rs.github.io/proptest/proptest/index.html"
+keywords = ["property", "testing", "quickcheck", "fuzz", "hypothesis"]
+categories = ["development-tools::testing"]
+rust-version = "1.65"
 
 [lib]
 proc-macro = true