Added documentation url to Cargo.toml for crates.io visibility

Author: TheDan64

Cargo.toml

@@ -3,6 +3,7 @@ name = "inkwell"
 version = "0.1.0"
 authors = ["Daniel Kolsoi <[email protected]>"]
 description = "Inkwell aims to help you pen your own programming languages by safely wrapping llvm-sys."
+documentation = "https://thedan64.github.io/inkwell/"
 repository = "https://github.com/TheDan64/inkwell"
 readme = "README.md"
 keywords = ["llvm", "safe", "wrapper"]