Adding documentation before the release for GATK wiki page

public/java/src/org/broadinstitute/sting/gatk/filters/PlatformFilter.java

@@ -36,7 +36,7 @@ import org.broadinstitute.sting.utils.sam.ReadUtils;
  * @version 0.1
  */
 public class PlatformFilter extends ReadFilter {
-    @Argument(fullName = "PLFilterName", shortName = "PLFilterName", doc="Discard reads with RG:PL attribute containing this strign", required=false)
+    @Argument(fullName = "PLFilterName", shortName = "PLFilterName", doc="Discard reads with RG:PL attribute containing this string", required=false)
     protected String[] PLFilterNames;
 
     public boolean filterOut(SAMRecord rec) {

public/java/src/org/broadinstitute/sting/gatk/walkers/PrintReadsWalker.java

@@ -68,6 +68,13 @@ import org.broadinstitute.sting.gatk.refdata.ReadMetaDataTracker;
  *   -I input1.bam \
  *   -I input2.bam \
  *   --read_filter MappingQualityZero
+ *
+ * java -Xmx2g -jar GenomeAnalysisTK.jar \
+ *   -R ref.fasta \
+ *   -T PrintReads \
+ *   -o output.bam \
+ *   -I input.bam \
+ *   -n 2000
  * </pre>
  *
  */