Explanation of ref_level argument of DeseqDataSet() in the tutorials

[ozanozisik]

Hello,
While contrast argument of DeseqStats() is explained well in "A simple PyDESeq2 workflow", ref_level argument of DeseqDataSet() and its importance to match the contrasts in design_matrix and DeseqStats are not described. Although the error message directly suggests a solution, seeing it beforehand in the documentation would be better.
Thank you for the tool. Regards.