fix(swagger): 修正Knife4j配置并补充接口注解

- 更新扫描包路径为正确包名 com.yolo.keyborad.controller
- 修正文档标题与项目名 keyborad-backend 保持一致
- 在 DemoController 添加 @Api 及 @ApiOperation 注解

src/main/java/com/yolo/keyborad/controller/DemoController.java

@@ -2,6 +2,10 @@ package com.yolo.keyborad.controller;
 
 import com.yolo.keyborad.common.BaseResponse;
 import com.yolo.keyborad.common.ResultUtils;
+import io.swagger.annotations.Api;
+import io.swagger.annotations.ApiOperation;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.web.bind.annotation.CrossOrigin;
 import org.springframework.web.bind.annotation.GetMapping;
@@ -16,11 +20,12 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("/demo")
 @Slf4j
 @CrossOrigin
+@Api(tags = "测试控制器")
 public class DemoController {
 
     @GetMapping("/test")
-    public BaseResponse<String> hostsInfo(){
-
+    @ApiOperation("测试接口")
+    public BaseResponse<String> testDemo(){
         return  ResultUtils.success("hello world");
     }
 }