README: Small cleanup

README.md

@@ -78,7 +78,10 @@ To install Nix from any commit, go to [the corresponding installer_test action](
 ### How do I print nixpkgs version I have configured?
 
 
-```nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'```
+```yaml
+- name: Print nixpkgs version
+  run: nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'
+```
 
 ### How can I run NixOS tests?
 
@@ -90,7 +93,6 @@ With the following inputs:
     extra_nix_config: "system-features = nixos-test benchmark big-parallel kvm"
 ```
 
-
 [Note that there's no hardware acceleration on GitHub Actions.](https://github.com/actions/virtual-environments/issues/183#issuecomment-610723516).
 
 ### How can I install packages via nix-env from the specified `nix_path`?