chore: small improvements in interactive-vm.md

Author: gabyx

Diff for: docs/interactive-vm.md

@@ -1,10 +1,10 @@
-# Running Interactive VMs with disko
+# Running Interactive VMs with `disko`
 
 disko now exports its own flavor of interactive VMs (similiar to
 config.system.build.vm). Simply import the disko module and build the vm runner
 with:
 
-```
+```bash
 nix run -L '.#nixosConfigurations.mymachine.config.system.build.vmWithDisko'
 ```
 
@@ -21,6 +21,7 @@ option:
 }
 ```
 
-extraConfig that is set in disko.tests.extraConfig is also applied to the
-interactive VMs. imageSize of the VMs will be determined by the imageSize in the
-disk type in your disko config. memorySize is set by disko.memSize
+Extra configuration that is set in `disko.tests.extraConfig` is also applied to the
+interactive VMs. The image size of the VMs will be determined by the 
+`disko.devices.disk.<name>.imageSize` 
+specifications. The memory size is set by `disko.memSize`.