Add license and cargo metadata

Cargo.toml

@@ -1,7 +1,14 @@
 [package]
 name = "tuemensa"
+categories = ["command-line-utilities"]
 version = "0.2.0"
 edition = "2021"
+license = "MIT"
+authors = ["structix"]
+description = "A simple command-line tool designed to retrieve the current meal plans for the canteens at Eberhard Karls Universität Tübingen."
+repository = "https://github.com/STRUCTiX/tuemensa"
+readme = "README.md"
+keywords = ["cli", "canteen", "university", "tuebingen"]
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html