add parameter_meta

gatk.wdl

@@ -960,6 +960,8 @@ task HaplotypeCaller {
         contamination: {description: "Equivalent to HaplotypeCaller's `-contamination` option.", category: "advanced"}
         outputMode: {description: "Specifies which type of calls we should output. Same as HaplotypeCaller's `--output-mode` option.",
                      category: "advanced"}
+        emitRefConfidence: {description: "Whether to include reference calls. Three modes: 'NONE', 'BP_RESOLUTION' and 'GVCF'",
+                            category: "advanced"}
         dbsnpVCF: {description: "A dbSNP VCF.", category: "common"}
         dbsnpVCFIndex: {description: "The index for the dbSNP VCF.", category: "common"}
         pedigree: {description: "Pedigree file for determining the population \"founders\"", category: "common"}