ci: Optimize code coverage report and testing process

.github/workflows/main.yml

@@ -24,7 +24,8 @@ jobs:
         run: go mod download
 
       - name: Run tests
-        run: go test -count=1 -coverprofile=coverage.txt ./...
+        run: go test -count=1 -coverprofile=coverage.txt ./... &&
+          grep -v "^github.com/go-spring/spring-core/gs/examples" coverage.txt > coverage.txt.tmp && mv coverage.txt.tmp coverage.txt
 
       - name: Upload results to Codecov
         uses: codecov/codecov-action@v5

README.md

@@ -1,5 +1,7 @@
 # spring-core
 
+[![codecov](https://codecov.io/gh/go-spring/spring-core/branch/main/graph/badge.svg)](https://codecov.io/gh/go-spring/spring-core)
+
 # 介绍
 
 Go-Spring 是为 Go 开发者打造的轻量级微服务框架，灵感来源于 Java 的 Spring 和 Spring Boot。