Update README

README.md

@@ -1,9 +1,16 @@
 
 # Platform Info
 
+[![Cross-platform tests](https://github.com/karip/platform-info/actions/workflows/rust.yml/badge.svg)](https://github.com/karip/platform-info/actions/workflows/rust.yml)
+
 A simple Rust application to print out platform CPU architecture,
 endianness and pointer width.
 
+This repository also shows how to use GitHub actions to test
+the code on 64-bit x86_64 little-endian and 32-bit PowerPC big-endian CPUs.
+It uses [setup-cross-toolchain-action](https://github.com/marketplace/actions/setup-toolchains-for-cross-compilation-and-cross-testing-for-rust) to run the actions for `x86_64-unknown-linux-gnu` and `powerpc-unknown-linux-gnu`.
+See the [rust.yml](.github/workflows/rust.yml) file how the action is configured.
+
 ## Running
 
     > cargo run