virsh-undefine: add page (#5847)

pages/common/virsh-undefine.md

@@ -0,0 +1,16 @@
+# virsh-undefine
+
+> Delete a virtual machine.
+> More information: <https://manned.org/virsh>.
+
+- Delete only the virtual machine configuration file:
+
+`virsh undefine --domain {{vm_name}}`
+
+- Delete the configuration file and all associated storage volumes:
+
+`virsh undefine --domain {{vm_name}} --remove-all-storage`
+
+- Delete the configuration file and the specified storage volumes using the target name or the source name (as obtained from the `virsh domblklist` command):
+
+`virsh undefine --domain {{vm_name}} --storage {{sda,path/to/source}}`