enh(boilerplate): add missing reference for MNI152NLin6Asym

Author: oesteban

fmriprep/data/boilerplate.bib

@@ -100,6 +100,17 @@ @article{mni152nlin2009casym
     year = 2009
 }
 
+@article{mni152nlin6asym,
+    author = {Evans, AC and Janke, AL and Collins, DL and Baillet, S},
+    title = {Brain templates and atlases},
+    doi = {10.1016/j.neuroimage.2012.01.024},
+    journal = {NeuroImage},
+    volume = {62},
+    number = {2},
+    pages = {911--922},
+    year = 2012
+}
+
 @article{ants,
     author = {Avants, B.B. and Epstein, C.L. and Grossman, M. and Gee, J.C.},
     doi = {10.1016/j.media.2007.06.004},