Update TODO with additional notes
Update TODO with additional notes

jberkenbilt/qpdf,jberkenbilt/qpdf,jberkenbilt/qpdf,qpdf/qpdf,jberkenbilt/qpdf,qpdf/qpdf,qpdf/qpdf,qpdf/qpdf,qpdf/qpdf,jberkenbilt/qpdf