add: 增加协议文档

docs/通信协议/活动分类.md

@@ -0,0 +1,46 @@
+## 现有协议 
+
+GET api/category
+
+returns
+```json
+{
+  "status": 200,
+  "msg": "ok",
+  "data": [
+    {
+      "id": 10,
+      "pid": 0,
+      "cate_name": "活动",
+      "pic": "http://kaifa.crmeb.net/uploads/attach/2020/03/20200318/2c9fd486092555d91efff5c6e5e383d6.jpg",
+      "children": [
+        {
+          "id": 1,
+          "cate_name": "天天免单",
+          "pic": "http://kaifa.crmeb.net/uploads/attach/2020/03/20200318/f1c66db0b9bb23d7b36013d794492d67.jpg"
+        },
+        {
+          "id": 2,
+          "cate_name": "活动2",
+          "pic": "http://kaifa.crmeb.net/uploads/attach/2020/03/20200318/2ab5ea85f26c5bcdf2559136c7a3b22d.jpg"
+        },
+        {
+          "id": 3,
+          "cate_name": "活动N",
+          "pic": "http://kaifa.crmeb.net/uploads/attach/2020/03/20200318/2c9fd486092555d91efff5c6e5e383d6.jpg"
+        },
+        {
+          "id": 199,
+          "cate_name": "黑洞",
+          "pic": "http://kaifa.crmeb.net/uploads/attach/2020/03/20200318/2c9fd486092555d91efff5c6e5e383d6.jpg"
+        }
+      ]
+    }
+  ]
+}
+// 说明
+- 协议格式不变
+- 商品类活动都在"活动"分类下, 其 id 固定为 10
+- 子分类中, id 从 1 往后排
+- 挖矿活动 id 固定为 199
+```