docs: 添加 SemVer 规范链接

在类注释中添加了指向 Semantic Versioning 2.0.0 规范的链接。

plusone-commons/src/main/java/xyz/zhouxy/plusone/commons/model/SemVer.java

@@ -39,6 +39,8 @@ import xyz.zhouxy.plusone.commons.util.StringTools;
  *
  * @author ZhouXY108 <luquanlion@outlook.com>
  * @since 1.1.0
+ *
+ * @see <a href="https://semver.org/">Semantic Versioning 2.0.0</a>
  */
 public class SemVer implements Comparable<SemVer>, Serializable {
     private static final long serialVersionUID = 458265121025514002L;