Initialize Spring Boot project with basic structure and configuration

src/main/java/com/example/productaffinity/ProductAffinityApplication.java

@@ -0,0 +1,12 @@
+package com.example.productaffinity;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class ProductAffinityApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(ProductAffinityApplication.class, args);
+    }
+}