Updated Hadoop Compatible File System (markdown)

Hadoop-Compatible-File-System.md

@@ -72,6 +72,7 @@ Both reads and writes are working fine.
 * Configure Hadoop to use SeaweedFS in `etc/hadoop/conf/core-site.xml`. `core-site.xml` resides on each node in the Hadoop cluster. You must add the same properties to each instance of `core-site.xml`. There are several properties to modify:
     1. `fs.seaweedfs.impl`: This property defines the Seaweed HCFS implementation classes that are contained in the SeaweedFS HDFS client JAR. It is required.
     1. `fs.defaultFS`: This property defines the default file system URI to use. It is optional if a path always has prefix `seaweedfs://localhost:8888`.
+    1. `fs.AbstractFileSystem.seaweedfs.impl`: Add the SeaweedFS implementation of Hadoop AbstractFileSystem to delegates to the existing SeaweedFS FileSystem and is only necessary for use with Hadoop 3.x.
 
 ```
 <configuration>
@@ -83,6 +84,10 @@ Both reads and writes are working fine.
         <name>fs.defaultFS</name>
         <value>seaweedfs://localhost:8888</value>
     </property>
+    <property>
+       <name>fs.AbstractFileSystem.seaweedfs.impl</name>
+       <value>seaweed.hdfs.SeaweedAbstractFileSystem</value>
+    </property>
 </configuration>
 ```
 * Deploy the SeaweedFS HDFS client jar