add blocks/layout-antd-col-12-12

+{
+  "name": "两栏布局 Col 12-12",
+  "description": "Antd 的 col-12-12 布局。",
+  "dependencies": {
+    "antd": "^3.10.9"
+  },
+  "block": {
+    "category": "布局"
+  }
+}

+import React from 'react';
+import { Row, Col } from 'antd';
+
+export default () => {
+  return (
+    <Row>
+      <Col span={12}>INSERT_BLOCK_PLACEHOLDER:Col 12</Col>
+      <Col span={12}>INSERT_BLOCK_PLACEHOLDER:Col 12</Col>
+    </Row>
+  );
+}