Added github workflow

.github/workflows/build-on-merge.yml

@@ -0,0 +1,52 @@
+name: Build and Test
+
+on:
+  push:
+    branches:
+      - main  # Run the workflow on pushes to the 'main' branch
+  pull_request:
+    branches:
+      - main  # Optional: Run checks on pull requests targeting 'main'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      # Step 1: Check out the code
+      - name: Check out the repository
+        uses: actions/checkout@v3
+
+      # Step 2: Set up Go environment
+      - name: Set up Go
+        uses: actions/setup-go@v4
+        with:
+          go-version: 1.23
+
+      # Step 3: Cache Go dependencies
+      - name: Cache Go modules
+        uses: actions/cache@v3
+        with:
+          path: ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+
+      # Step 4: Run tests
+      - name: Run tests
+        run: |
+          go mod tidy
+          go test ./...
+
+      # Step 5: Build the application
+      - name: Build the application
+        run: |
+          mkdir -p build
+          go build -o build/mailculator .
+
+      # Step 6: Archive the build (optional)
+      - name: Upload Build Artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: mailculator
+          path: build/mailculator