doc: fixed broken link, tweaked wording in  uix/filechooser.py
doc: fixed broken link, tweaked wording in  uix/filechooser.py

habibmasuro/kivy,LogicalDash/kivy,habibmasuro/kivy,Ramalus/kivy,MiyamotoAkira/kivy,rnixx/kivy,ernstp/kivy,habibmasuro/kivy,darkopevec/kivy,akshayaurora/kivy,tony/kivy,aron-bordin/kivy,jffernandez/kivy,Ramalus/kivy,LogicalDash/kivy,jkankiewicz/kivy,rafalo1333/kivy,inclement/kivy,andnovar/kivy,KeyWeeUsr/kivy,kived/kivy,iamutkarshtiwari/kivy,edubrunaldi/kivy,Cheaterman/kivy,rnixx/kivy,bhargav2408/kivy,xiaoyanit/kivy,manthansharma/kivy,arlowhite/kivy,mSenyor/kivy,viralpandey/kivy,darkopevec/kivy,manthansharma/kivy,manashmndl/kivy,viralpandey/kivy,bliz937/kivy,bhargav2408/kivy,rafalo1333/kivy,manashmndl/kivy,ernstp/kivy,manthansharma/kivy,jffernandez/kivy,jehutting/kivy,Cheaterman/kivy,mSenyor/kivy,aron-bordin/kivy,kivy/kivy,xpndlabs/kivy,rnixx/kivy,KeyWeeUsr/kivy,iamutkarshtiwari/kivy,bionoid/kivy,MiyamotoAkira/kivy,aron-bordin/kivy,el-ethan/kivy,bionoid/kivy,jehutting/kivy,Cheaterman/kivy,matham/kivy,manashmndl/kivy,bhargav2408/kivy,jegger/kivy,Cheaterman/kivy,bliz937/kivy,bionoid/kivy,jffernandez/kivy,akshayaurora/kivy,vitorio/kivy,iamutkarshtiwari/kivy,youprofit/kivy,cbenhagen/kivy,cbenhagen/kivy,ernstp/kivy,autosportlabs/kivy,janssen/kivy,kivy/kivy,darkopevec/kivy,matham/kivy,matham/kivy,jegger/kivy,vitorio/kivy,autosportlabs/kivy,LogicalDash/kivy,janssen/kivy,xiaoyanit/kivy,KeyWeeUsr/kivy,janssen/kivy,thezawad/kivy,CuriousLearner/kivy,bliz937/kivy,Ramalus/kivy,jkankiewicz/kivy,KeyWeeUsr/kivy,el-ethan/kivy,andnovar/kivy,arlowhite/kivy,vitorio/kivy,youprofit/kivy,inclement/kivy,kived/kivy,VinGarcia/kivy,kivy/kivy,manthansharma/kivy,tony/kivy,andnovar/kivy,janssen/kivy,cbenhagen/kivy,xiaoyanit/kivy,rafalo1333/kivy,kived/kivy,matham/kivy,viralpandey/kivy,VinGarcia/kivy,mSenyor/kivy,autosportlabs/kivy,arlowhite/kivy,MiyamotoAkira/kivy,akshayaurora/kivy,aron-bordin/kivy,jkankiewicz/kivy,ernstp/kivy,youprofit/kivy,edubrunaldi/kivy,darkopevec/kivy,VinGarcia/kivy,jegger/kivy,jehutting/kivy,inclement/kivy,tony/kivy,CuriousLearner/kivy,xpndlabs/kivy,thezawad/kivy,LogicalDash/kivy,el-ethan/kivy,MiyamotoAkira/kivy,CuriousLearner/kivy,jffernandez/kivy,bionoid/kivy,jegger/kivy,jkankiewicz/kivy,thezawad/kivy,xpndlabs/kivy,edubrunaldi/kivy