Add rust testing

src/SUMMARY.md

@@ -8,6 +8,7 @@
     - [Testing](./dev/golang/testing.md)
   - [Rust](./dev/rust/main.md)
     - [serde](./dev/rust/serde.md)
+    - [Testing](./dev/rust/testing.md)
   - [Web](./dev/web/main.md)
     - [front](./dev/web/front/main.md)
       - [babel and babel-preset-stage-2](./dev/web/front/babel-preset-stage-2.md)

src/dev/rust/testing.md

@@ -0,0 +1,9 @@
+# Testing
+
+## `Cargo test` and `println!`
+
+To see stdout when using cargo run (kudos CobaltVelvet)
+
+```shell
+cargo run -- --nocapture
+```