Update README.md

Author: leopardracer

embedded/README.md

@@ -1,11 +1,11 @@
 ## Embedded tests
 
 These no-std tests are a bit peculiar.
-They are cross compiled to ARM and run in an emulator.
+They are cross-compiled to ARM and run in an emulator.
 Here's why:
 
  - We want to build for an exotic platform to help make sure `std` doesn't sneak in by accident.
 
  - We use an emulator and build something runnable,
    rather than merely testing whether a library builds,
-   because we want to actually run our integration test.
+   because we want to actually run our integration tests.