add contributions per chapter

@anton-akhmerov, could you provide some feedback on these changes?

chapter_supercurrent/supercurrent.tex

@@ -4,6 +4,7 @@
 \blfootnote{This chapter has been previously published as
 Kun Zuo, Vincent Mourik, Daniel B. Szombati, Bas Nijholt, David J. Van Woerkom, Attila Geresdi, Jun Chen, Viacheslav P. Ostroukh, Anton R. Akhmerov, Sebasti{\'e}n R. Plissard, Diana Car, Erik P. A. M. Bakkers, Dmitry I. Pikulin, Leo P. Kouwenhoven, and Sergey M. Frolov, \textit{Supercurrent interference in few-mode nanowire Josephson junctions}, \href{https://doi.org/10.1103/PhysRevLett.119.187704}{Phys. Rev. Lett.~\textbf{119}, 187704, (2017)}
 }
+\blfootnote{My contributions to this work include writing parts of the paper, implementing the numerical methods to calculate supercurrents, and performing the numerical simulations.}
 
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