HADOOP-14045. Aliyun OSS documentation missing from website. Contributed by Yiqun Lin.

hadoop-project/src/site/site.xml

@@ -148,6 +148,7 @@
     </menu>
     
     <menu name="Hadoop Compatible File Systems" inherit="top">
+      <item name="Aliyun OSS" href="hadoop-aliyun/tools/hadoop-aliyun/index.html"/>
       <item name="Amazon S3" href="hadoop-aws/tools/hadoop-aws/index.html"/>
       <item name="Azure Blob Storage" href="hadoop-azure/index.html"/>
       <item name="Azure Data Lake Storage"