added gitbook docs

docs/QuickStart/Installation.md

@@ -0,0 +1,22 @@
+# 安装
+
+最快安装Crawlab的方式是克隆一份代码到本地
+
+```bash
+git clone https://github.com/tikazyq/crawlab
+```
+
+安装类库
+
+```bash
+# 安装后台类库
+pip install -r requirements.txt
+```
+
+```bash
+# 安装前台类库
+cd frontend
+npm install
+```
+
+