docs: Default machine type is q35 meanwhile

Fixes: kata-containers#3412

Signed-off-by: Sebastian Hasler <[email protected]>

Author: haslersn

docs/design/virtualization.md

@@ -40,7 +40,7 @@ Kata Containers with QEMU has complete compatibility with Kubernetes.
 
 Depending on the host architecture, Kata Containers supports various machine types,
 for example `pc` and `q35` on x86 systems, `virt` on ARM systems and `pseries` on IBM Power systems. The default Kata Containers
-machine type is `pc`. The machine type and its [`Machine accelerators`](#machine-accelerators) can
+machine type is `q35`. The machine type and its [`Machine accelerators`](#machine-accelerators) can
 be changed by editing the runtime [`configuration`](architecture/README.md#configuration) file.
 
 Devices and features used: