feat(config): Schema validator, initial config merger setup

config.schema.json

@@ -88,6 +88,12 @@
                                     },
                                     "maxItems": 5,
                                     "minItems": 1
+                                },
+                                "count": {
+                                    "type": "number",
+                                    "description": "The number of mirrors to add to the list",
+                                    "maximum": 20,
+                                    "minimum": 3
                                 }
                             },
                             "required": [