Add some badges to README (#154)

README.md

@@ -1,5 +1,8 @@
 # Frontier
 
+![GitHub Workflow Status](https://img.shields.io/github/workflow/status/paritytech/frontier/Rust)
+![Matrix](https://img.shields.io/matrix/frontier:matrix.org)
+
 Frontier is Substrate's Ethereum compatibility layer. It allows you to run
 unmodified Ethereum dapps.
 
@@ -57,4 +60,4 @@ git submodule update
 1. Override your local cargo config to point to your local substrate (pointing to your WIP branch): place `paths = ["path/to/substrate"]` in `~/.cargo/config`.
 2. You are good to go.
 
-Remember to comment out the override after it is done to avoid mysterious build issues on other repo.
+Remember to comment out the override after it is done to avoid mysterious build issues on other repo.