updated documentation curve_fit (#6863)
updated documentation curve_fit (#6863)

DOC: optimize: add a plot to curve_fit documentation example
aarchiba/scipy,Eric89GXL/scipy,lhilt/scipy,Stefan-Endres/scipy,matthew-brett/scipy,Stefan-Endres/scipy,gertingold/scipy,gertingold/scipy,andyfaff/scipy,pbrod/scipy,zerothi/scipy,andyfaff/scipy,arokem/scipy,josephcslater/scipy,jor-/scipy,ilayn/scipy,apbard/scipy,josephcslater/scipy,e-q/scipy,matthew-brett/scipy,kalvdans/scipy,perimosocordiae/scipy,pbrod/scipy,jakevdp/scipy,anntzer/scipy,lhilt/scipy,mdhaber/scipy,jakevdp/scipy,kalvdans/scipy,befelix/scipy,scipy/scipy,Eric89GXL/scipy,jakevdp/scipy,jamestwebber/scipy,aeklant/scipy,pizzathief/scipy,pizzathief/scipy,lhilt/scipy,WarrenWeckesser/scipy,josephcslater/scipy,dominicelse/scipy,gfyoung/scipy,matthew-brett/scipy,WarrenWeckesser/scipy,perimosocordiae/scipy,Stefan-Endres/scipy,gertingold/scipy,dominicelse/scipy,person142/scipy,gfyoung/scipy,anntzer/scipy,jjhelmus/scipy,jor-/scipy,nmayorov/scipy,pschella/scipy,arokem/scipy,endolith/scipy,person142/scipy,pschella/scipy,befelix/scipy,kalvdans/scipy,dominicelse/scipy,WarrenWeckesser/scipy,arokem/scipy,gfyoung/scipy,nmayorov/scipy,person142/scipy,grlee77/scipy,pschella/scipy,perimosocordiae/scipy,pschella/scipy,andyfaff/scipy,grlee77/scipy,Eric89GXL/scipy,WarrenWeckesser/scipy,arokem/scipy,pschella/scipy,mdhaber/scipy,pbrod/scipy,gertingold/scipy,jamestwebber/scipy,e-q/scipy,jjhelmus/scipy,pbrod/scipy,nmayorov/scipy,befelix/scipy,scipy/scipy,zerothi/scipy,endolith/scipy,perimosocordiae/scipy,jjhelmus/scipy,lhilt/scipy,aarchiba/scipy,ilayn/scipy,aarchiba/scipy,anntzer/scipy,grlee77/scipy,andyfaff/scipy,vigna/scipy,tylerjereddy/scipy,jamestwebber/scipy,Eric89GXL/scipy,person142/scipy,WarrenWeckesser/scipy,dominicelse/scipy,endolith/scipy,scipy/scipy,Eric89GXL/scipy,aeklant/scipy,person142/scipy,apbard/scipy,gertingold/scipy,mdhaber/scipy,endolith/scipy,tylerjereddy/scipy,aeklant/scipy,e-q/scipy,aarchiba/scipy,tylerjereddy/scipy,andyfaff/scipy,jakevdp/scipy,vigna/scipy,befelix/scipy,pizzathief/scipy,rgommers/scipy,josephcslater/scipy,perimosocordiae/scipy,matthew-brett/scipy,jjhelmus/scipy,grlee77/scipy,rgommers/scipy,lhilt/scipy,mdhaber/scipy,nmayorov/scipy,grlee77/scipy,aeklant/scipy,Stefan-Endres/scipy,kalvdans/scipy,jamestwebber/scipy,befelix/scipy,zerothi/scipy,ilayn/scipy,jjhelmus/scipy,apbard/scipy,endolith/scipy,e-q/scipy,ilayn/scipy,Stefan-Endres/scipy,jor-/scipy,jor-/scipy,ilayn/scipy,pizzathief/scipy,perimosocordiae/scipy,jamestwebber/scipy,dominicelse/scipy,Eric89GXL/scipy,apbard/scipy,nmayorov/scipy,mdhaber/scipy,rgommers/scipy,zerothi/scipy,jor-/scipy,vigna/scipy,vigna/scipy,tylerjereddy/scipy,aeklant/scipy,mdhaber/scipy,scipy/scipy,vigna/scipy,gfyoung/scipy,rgommers/scipy,endolith/scipy,Stefan-Endres/scipy,matthew-brett/scipy,aarchiba/scipy,pbrod/scipy,zerothi/scipy,tylerjereddy/scipy,WarrenWeckesser/scipy,jakevdp/scipy,zerothi/scipy,scipy/scipy,pbrod/scipy,scipy/scipy,e-q/scipy,gfyoung/scipy,ilayn/scipy,anntzer/scipy,andyfaff/scipy,josephcslater/scipy,anntzer/scipy,pizzathief/scipy,arokem/scipy,apbard/scipy,kalvdans/scipy,rgommers/scipy,anntzer/scipy