update with license in metadata

Author: hummusonrails

Cargo.toml

@@ -6,6 +6,7 @@ description = "A CLI tool to create a new Rocket webapp with ChatGPT integration
 authors = ["Ben Greenberg <bengreenberg@gmail.com>"]
 keywords = ["chatgpt", "rocket", "webapp", "cli"]
 readme = "README.md"
+license = "MIT"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html