Fix link in DemuxFastqs.scala (#938)

Fix markdown syntax

src/main/scala/com/fulcrumgenomics/fastq/DemuxFastqs.scala

@@ -234,7 +234,7 @@ object DemuxFastqs {
       |If multiple FASTQs are present for each sub-read, then the FASTQs for each sub-read should be concatenated together
       |prior to running this tool (ex. `cat s_R1_L001.fq.gz s_R1_L002.fq.gz > s_R1.fq.gz`).
       |
-      |(Read structures)[https://github.com/fulcrumgenomics/fgbio/wiki/Read-Structures] are made up of `<number><operator>`
+      |[Read structures](https://github.com/fulcrumgenomics/fgbio/wiki/Read-Structures) are made up of `<number><operator>`
       |pairs much like the `CIGAR` string in BAM files. Four kinds of operators are recognized:
       |
       |1. `T` identifies a template read