Merge #297

297: Tweak testing cargo-binutils r=eldruin a=winksaville

While following the instructions for cargo-binutils in 03-setup
the `cargo size -- -version` caused an error when following the
instructions:

``` console
$ cargo size -- -version
error: Error during execution of `cargo metadata`: error: could not find `Cargo.toml` in `C:\Users\wink` or any parent directory
```

The cause of the error is that you're not told to  be in a rust project
directory.

The solution I've chosen is to create a rust bin project, cd into the
project, run it and then do the `cargo size -- -version`.

Co-authored-by: Wink Saville <wink@saville.com>

src/03-setup/README.md

@@ -90,13 +90,24 @@ itmdump 0.3.1
 ``` console
 $ rustup component add llvm-tools-preview
 
-$ cargo install cargo-binutils --vers 0.3.0
+$ cargo install cargo-binutils
+
+$ cargo new test-size
+     Created binary (application) `test-size` package
+
+$ cd test-size
+
+$ cargo run
+    Finished dev [unoptimized + debuginfo] target(s) in 0.01s
+     Running `target\debug\test-size.exe`
+Hello, world!
 
 $ cargo size -- -version
+    Finished dev [unoptimized + debuginfo] target(s) in 0.50s
 LLVM (http://llvm.org/):
-  LLVM version 8.0.0svn
+  LLVM version 11.0.0-rust-1.49.0-stable
   Optimized build.
-  Default target: x86_64-unknown-linux-gnu
+  Default target: x86_64-pc-windows-msvc
   Host CPU: skylake
 ```