feat: add rust-script

external/rust-script/tests/data/script-short-without-main.rs

@@ -0,0 +1,9 @@
+// cargo-deps: boolinator="=0.1.0"
+// You can also leave off the version number, in which case, it's assumed
+// to be "*".  Also, the `cargo-deps` comment *must* be a single-line
+// comment, and it *must* be the first thing in the file, after the
+// shebang.
+use boolinator::Boolinator;
+
+println!("--output--");
+println!("{:?}", true.as_some(1));