Update readme with DOI

readme.txt

@@ -3,6 +3,8 @@ This folder contains the files for generating Fig 7 of:
 The Na+/K+-ATPase generically enables deterministic bursting in class I neurons by shearing the spike-onset bifurcation structure
 Mahraz Behbood, Louisiane Lemaire, Jan-Hendrik Schleimer, Susanne Schreiber
 
+DOI:10.5281/zenodo.11385327
+
 if you use these files, please cite the above paper as the reference.
 
 In some folders there are some biurcation data files, which we produced with XPPAUT. The files needed for producing these data files are in the 'XPPAUT files' folder.