Fix README path

Author: parasyte

cargo-n64/Cargo.toml

@@ -5,7 +5,7 @@ authors = ["Jay Oster <[email protected]>"]
 repository = "https://github.com/rust-console/cargo-n64"
 description = "Cargo subcommand to build Nintendo 64 ROMs"
 license = "MIT"
-readme = "README.md"
+readme = "../README.md"
 categories = ["command-line-utilities", "development-tools", "embedded"]
 keywords = ["cli", "cross", "compilation", "nintendo", "n64"]
 edition = "2018"