HADOOP-12959. Add additional github web site for ISA-L library (Li Bo via cmccabe)

BUILDING.txt

@@ -75,6 +75,7 @@ Optional packages:
   $ sudo apt-get install snappy libsnappy-dev
 * Intel ISA-L library for erasure coding
   Please refer to https://01.org/intel%C2%AE-storage-acceleration-library-open-source-version
+  (OR https://github.com/01org/isa-l)
 * Bzip2
   $ sudo apt-get install bzip2 libbz2-dev
 * Jansson (C Library for JSON)
@@ -188,11 +189,12 @@ Maven build goals:
 
  Intel ISA-L build options:
 
-   Intel ISA-L is a erasure coding library that can be utilized by the native code.
+   Intel ISA-L is an erasure coding library that can be utilized by the native code.
    It is currently an optional component, meaning that Hadoop can be built with
    or without this dependency. Note the library is used via dynamic module. Please
    reference the official site for the library details.
    https://01.org/intel%C2%AE-storage-acceleration-library-open-source-version
+   (OR https://github.com/01org/isa-l)
 
   * Use -Drequire.isal to fail the build if libisal.so is not found.
     If this option is not specified and the isal library is missing,