DOC: add citation file.
DOC: add citation file.

[SKIP CI]

perimosocordiae/scipy,rgommers/scipy,mdhaber/scipy,grlee77/scipy,zerothi/scipy,endolith/scipy,mdhaber/scipy,perimosocordiae/scipy,endolith/scipy,matthew-brett/scipy,ilayn/scipy,scipy/scipy,mdhaber/scipy,vigna/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,ilayn/scipy,perimosocordiae/scipy,matthew-brett/scipy,zerothi/scipy,anntzer/scipy,matthew-brett/scipy,Stefan-Endres/scipy,andyfaff/scipy,scipy/scipy,andyfaff/scipy,perimosocordiae/scipy,mdhaber/scipy,ilayn/scipy,vigna/scipy,ilayn/scipy,perimosocordiae/scipy,grlee77/scipy,scipy/scipy,zerothi/scipy,anntzer/scipy,anntzer/scipy,grlee77/scipy,matthew-brett/scipy,scipy/scipy,anntzer/scipy,andyfaff/scipy,endolith/scipy,endolith/scipy,rgommers/scipy,zerothi/scipy,anntzer/scipy,matthew-brett/scipy,andyfaff/scipy,ilayn/scipy,anntzer/scipy,scipy/scipy,zerothi/scipy,vigna/scipy,WarrenWeckesser/scipy,ilayn/scipy,Stefan-Endres/scipy,tylerjereddy/scipy,tylerjereddy/scipy,Stefan-Endres/scipy,grlee77/scipy,tylerjereddy/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,rgommers/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,andyfaff/scipy,mdhaber/scipy,tylerjereddy/scipy,WarrenWeckesser/scipy,WarrenWeckesser/scipy,rgommers/scipy,tylerjereddy/scipy,endolith/scipy,vigna/scipy,mdhaber/scipy,zerothi/scipy,rgommers/scipy,vigna/scipy,scipy/scipy,WarrenWeckesser/scipy,grlee77/scipy,endolith/scipy,andyfaff/scipy