change .sif to .img for singularity img

src/nf_modules/bedtools/fasta_from_bed.config

src/nf_modules/bowtie/indexing.config

src/nf_modules/bowtie/mapping_paired.config

src/nf_modules/bowtie/mapping_single.config

src/nf_modules/bowtie2/indexing.config

src/nf_modules/bowtie2/mapping_paired.config

src/nf_modules/bowtie2/mapping_single.config

src/nf_modules/bwa/indexing.config

src/nf_modules/bwa/mapping_paired.config

src/nf_modules/cutadapt/adaptor_removal_paired.config

src/nf_modules/cutadapt/adaptor_removal_single.config

src/nf_modules/cutadapt/trimming_paired.config

src/nf_modules/cutadapt/trimming_single.config

src/nf_modules/deeptools/bam_to_bigwig.config

src/nf_modules/deeptools/compute_matrix.config

src/nf_modules/deeptools/plot_profile.config

src/nf_modules/fastp/fastp_paired.config

src/nf_modules/fastp/fastp_single.config

src/nf_modules/fastqc/fastqc_paired.config

src/nf_modules/fastqc/fastqc_single.config