[SPARK-25677][DOC] spark.io.compression.codec = org.apache.spark.io.ZstdCompressionCodec throwing IllegalArgumentException Exception

## What changes were proposed in this pull request?
Documentation is updated with proper classname org.apache.spark.io.ZStdCompressionCodec

## How was this patch tested?
we used the  spark.io.compression.codec = org.apache.spark.io.ZStdCompressionCodec
and verified the logs.

Closes #22669 from shivusondur/CompressionIssue.

Authored-by: shivusondur <[email protected]>
Signed-off-by: hyukjinkwon <[email protected]>

Author: shivusondur

docs/configuration.md

@@ -954,7 +954,7 @@ Apart from these, the following properties are also available, and may be useful
     <code>org.apache.spark.io.LZ4CompressionCodec</code>,
     <code>org.apache.spark.io.LZFCompressionCodec</code>,
     <code>org.apache.spark.io.SnappyCompressionCodec</code>,
-    and <code>org.apache.spark.io.ZstdCompressionCodec</code>.
+    and <code>org.apache.spark.io.ZStdCompressionCodec</code>.
   </td>
 </tr>
 <tr>