Added a license field to cargo.toml

Cargo.toml

@@ -8,6 +8,7 @@ authors = ["Wynd <wyndftw@proton.me>"]
 description = "A simple and customizable heatmap for git repos"
 readme = "README.md"
 repository = "https://git.pixelatedw.xyz/wynd/git-heatmap"
+license = "MIT"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -30,4 +31,4 @@ incremental = true
 opt-level = 3
 strip = true
 lto = true
-codegen-units = 1
+codegen-units = 1