add some stuff

test/hello_world/.gitignore

@@ -0,0 +1,14 @@
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb

test/hello_world/Cargo.toml

@@ -3,6 +3,5 @@ name = "hello_world"
 version = "0.1.0"
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
+rand = "0.8.5"

test/hello_world/src/main.rs

@@ -1,3 +1,8 @@
+use rand::Rng;
+
 fn main() {
+    let mut rng = rand::thread_rng();
+
     println!("Hello, world!");
+    println!("A random number: {}", rng.gen::<u64>());
 }