Added DB validation for warnings

validation/warnings.json

@@ -1,6 +1,28 @@
 {
     "$jsonSchema": {
-        "required": [],
-        "properties": {}
+        "required": [
+            "user",
+            "admin",
+            "date",
+            "reason"
+        ],
+        "properties": {
+            "user": {
+                "bsonType": ["int", "long"],
+                "description": "Telegram ID of user"
+            },
+            "admin": {
+                "bsonType": ["int", "long"],
+                "description": "Telegram ID of admin"
+            },
+            "date": {
+                "bsonType": "date",
+                "description": "Date and time of getting"
+            },
+            "reason": {
+                "bsonType": "string",
+                "description": "Broken rule or admin's comment"
+            }
+        }
     }
 }