HDFS-12622. Fix enumerate in HDFSErasureCoding.md. Contributed by Yiqun Lin.

hadoop-hdfs-project/hadoop-hdfs/src/site/markdown/HDFSErasureCoding.md

@@ -140,6 +140,7 @@ Deployment
 ### Enable Intel ISA-L
 
   HDFS native implementation of default RS codec leverages Intel ISA-L library to improve the encoding and decoding calculation. To enable and use Intel ISA-L, there are three steps.
+
   1. Build ISA-L library. Please refer to the official site "https://github.com/01org/isa-l/" for detail information.
   2. Build Hadoop with ISA-L support. Please refer to "Intel ISA-L build options" section in "Build instructions for Hadoop" in (BUILDING.txt) in the source code.
   3. Use `-Dbundle.isal` to copy the contents of the `isal.lib` directory into the final tar file. Deploy Hadoop with the tar file. Make sure ISA-L is available on HDFS clients and DataNodes.