DOC: optimize: add Assignment problems section.
DOC: optimize: add Assignment problems section.

grlee77/scipy,zerothi/scipy,tylerjereddy/scipy,e-q/scipy,grlee77/scipy,endolith/scipy,tylerjereddy/scipy,scipy/scipy,e-q/scipy,Eric89GXL/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,ilayn/scipy,Eric89GXL/scipy,scipy/scipy,rgommers/scipy,mdhaber/scipy,perimosocordiae/scipy,perimosocordiae/scipy,zerothi/scipy,mdhaber/scipy,WarrenWeckesser/scipy,andyfaff/scipy,Stefan-Endres/scipy,andyfaff/scipy,Stefan-Endres/scipy,scipy/scipy,Stefan-Endres/scipy,matthew-brett/scipy,scipy/scipy,grlee77/scipy,anntzer/scipy,tylerjereddy/scipy,grlee77/scipy,perimosocordiae/scipy,endolith/scipy,ilayn/scipy,tylerjereddy/scipy,WarrenWeckesser/scipy,e-q/scipy,zerothi/scipy,e-q/scipy,WarrenWeckesser/scipy,matthew-brett/scipy,vigna/scipy,vigna/scipy,ilayn/scipy,endolith/scipy,mdhaber/scipy,rgommers/scipy,matthew-brett/scipy,ilayn/scipy,andyfaff/scipy,grlee77/scipy,scipy/scipy,rgommers/scipy,zerothi/scipy,Eric89GXL/scipy,anntzer/scipy,rgommers/scipy,zerothi/scipy,endolith/scipy,mdhaber/scipy,vigna/scipy,andyfaff/scipy,e-q/scipy,vigna/scipy,ilayn/scipy,matthew-brett/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,matthew-brett/scipy,WarrenWeckesser/scipy,endolith/scipy,ilayn/scipy,endolith/scipy,rgommers/scipy,vigna/scipy,andyfaff/scipy,mdhaber/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,Eric89GXL/scipy,anntzer/scipy,anntzer/scipy,Eric89GXL/scipy,mdhaber/scipy,perimosocordiae/scipy,tylerjereddy/scipy,scipy/scipy,anntzer/scipy,andyfaff/scipy,Stefan-Endres/scipy,anntzer/scipy,zerothi/scipy