note: -- indicates an optional argument
Finds top peaks from association test results from GENESIS saved by chromsomes in format "prefix_chr1.RData"
Takes arguemnts:
--prefix", ex. "prefix_chr1.RData"
--p_min", maximum p-value below which to search for peaks, default = 5e-4
--top", number of SNPs peaks to save, default = NULL
--window", bp distance within which SNPs should be grouped into a peak", default = 15000
--out_file", file to save SNP peaks, default = "SNP_peaks.rds"