Update README.md

Way more understandable usage section

README.md

@@ -2,14 +2,25 @@
 Cargo command to work with Nintendo 3DS project binaries. Based on cargo-psp.
 
 # Usage
-While you can set the nightly version of Rust as default for the project you're working on (`rustup override nightly`), my suggested method is:
-`cargo +nightly 3ds`. \
-The commands are the same as cargo ("run" also uses 3dslink, so you can directly use `run` to compile and run on your system).
+Use the nightly toolchain to build 3DS apps (either by using `rustup override nightly` for the project directory or by adding `+nightly` in the `cargo` invocation).
 
-# Examples: 
-`cargo +nightly 3ds build` \
-`cargo +nightly 3ds run --release`
+Available commands:
+```
+    build           build a 3dsx executable.
+    run             build a 3dsx executable and send it to a device with 3dslink.
+    test            build a 3dsx executable from unit/integration tests and send it to a device.
+    <cargo-command> execute some other Cargo command with 3ds options configured (ex. check or clippy).
+```
+    
+Additional arguments will be passed through to `<cargo-command>`. Some that are supported include:
+```
+    [build | run | test] --release
+    test --no-run
+```
+    
+Other flags and commands may work, but haven't been tested.
 
-You can pass or not `--release` to build with debug symbols or not, and this works for both `build` and `run`.
-
-Any other parameters you pass after the command will be passed during the compiling stage to `cargo`.
+# Examples
+`cargo 3ds build` \
+`cargo 3ds run --release` \
+`cargo 3ds test --no-run`