sim: update README.rst with information on features
The README file is missing extra information about how to run all the
different test configurations; add this in.
@@ -38,6 +38,13 @@ this should download and compile the necessary dependencies, compile
the relevant modules from mcuboot, build the simulator, and run the
tests.
+There are several different features you can test. For example,
+testing RSA signatures can be done with::
+
+ $ cargo test --features sig-rsa
+
+For a complete list of features, see Cargo.toml.
+
Debugging
=========
