DOC: sparse.linalg: clarify lsqr docstring (#11703)
DOC: sparse.linalg: clarify lsqr docstring (#11703)

Improves docstring with consistent L2-norm contents.
Eric89GXL/scipy,scipy/scipy,Eric89GXL/scipy,tylerjereddy/scipy,matthew-brett/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,zerothi/scipy,WarrenWeckesser/scipy,ilayn/scipy,ilayn/scipy,e-q/scipy,tylerjereddy/scipy,person142/scipy,perimosocordiae/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,mdhaber/scipy,grlee77/scipy,person142/scipy,nmayorov/scipy,ilayn/scipy,WarrenWeckesser/scipy,anntzer/scipy,endolith/scipy,rgommers/scipy,endolith/scipy,WarrenWeckesser/scipy,tylerjereddy/scipy,anntzer/scipy,e-q/scipy,Eric89GXL/scipy,mdhaber/scipy,pizzathief/scipy,e-q/scipy,rgommers/scipy,perimosocordiae/scipy,andyfaff/scipy,matthew-brett/scipy,grlee77/scipy,zerothi/scipy,scipy/scipy,zerothi/scipy,Stefan-Endres/scipy,ilayn/scipy,pizzathief/scipy,andyfaff/scipy,Eric89GXL/scipy,matthew-brett/scipy,Eric89GXL/scipy,perimosocordiae/scipy,grlee77/scipy,vigna/scipy,rgommers/scipy,pizzathief/scipy,tylerjereddy/scipy,person142/scipy,matthew-brett/scipy,grlee77/scipy,Stefan-Endres/scipy,andyfaff/scipy,nmayorov/scipy,perimosocordiae/scipy,zerothi/scipy,rgommers/scipy,anntzer/scipy,rgommers/scipy,mdhaber/scipy,e-q/scipy,ilayn/scipy,anntzer/scipy,scipy/scipy,e-q/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,mdhaber/scipy,grlee77/scipy,nmayorov/scipy,scipy/scipy,Stefan-Endres/scipy,andyfaff/scipy,vigna/scipy,vigna/scipy,andyfaff/scipy,Stefan-Endres/scipy,endolith/scipy,endolith/scipy,anntzer/scipy,endolith/scipy,person142/scipy,nmayorov/scipy,tylerjereddy/scipy,nmayorov/scipy,endolith/scipy,scipy/scipy,andyfaff/scipy,vigna/scipy,pizzathief/scipy,WarrenWeckesser/scipy,zerothi/scipy,matthew-brett/scipy,scipy/scipy,zerothi/scipy,ilayn/scipy,perimosocordiae/scipy,anntzer/scipy,vigna/scipy,mdhaber/scipy,pizzathief/scipy,person142/scipy,mdhaber/scipy