Update release notes for Nix 1.5.3
Update release notes for Nix 1.5.3

ehmry/nix,vizanto/nix,pikajude/nix,rowhit/nix,garbas/nix,bjornfor/nix,garbas/nix,ehmry/nix,bjornfor/nix,dtzWill/nix,nbp/nix,edolstra/nix,joelmo/nix,dezgeg/nix,edolstra/nix,jcumming/nix,tchajed/nix,zimbatm/nix,gebner/nix,tchajed/nix,ysangkok/nix,ehmry/nix,zimbatm/nix,dezgeg/nix,shlevy/nix,ysangkok/nix,peti/nix,jcumming/nix,vizanto/nix,gridaphobe/nix,gridaphobe/nix,edolstra/nix,vcunat/nix,NixOS/nix,dezgeg/nix,rycee/nix,tchajed/nix,shlevy/nix,garbas/nix,shlevy/nix,dtzWill/nix,offlinehacker/nix,dtzWill/nix,bennofs/nix,rycee/nix,bjornfor/nix,vcunat/nix,offlinehacker/nix,acowley/nix,ttuegel/nix,ehmry/nix,vcunat/nix,edolstra/nix,layus/nix,peti/nix,ehmry/nix,wmertens/nix,NixOS/nix,acowley/nix,wmertens/nix,bjornfor/nix,rycee/nix,ysangkok/nix,layus/nix,pikajude/nix,gridaphobe/nix,bennofs/nix,dtzWill/nix,rycee/nix,offlinehacker/nix,peti/nix,aucampia/nix,rowhit/nix,gebner/nix,ttuegel/nix,puffnfresh/nix,nbp/nix,jcumming/nix,shlevy/nix,ttuegel/nix,acowley/nix,offlinehacker/nix,ehmry/nix,joelmo/nix,nbp/nix,vizanto/nix,dezgeg/nix,zimbatm/nix,aucampia/nix,aucampia/nix,layus/nix,rowhit/nix,gebner/nix,pikajude/nix,ttuegel/nix,wmertens/nix,bennofs/nix,rycee/nix,vcunat/nix,vizanto/nix,zimbatm/nix,puffnfresh/nix,dtzWill/nix,jcumming/nix,rowhit/nix,shlevy/nix,gebner/nix,aucampia/nix,tchajed/nix,joelmo/nix,wmertens/nix,puffnfresh/nix,garbas/nix,nbp/nix,NixOS/nix,layus/nix,gridaphobe/nix,edolstra/nix,NixOS/nix,puffnfresh/nix,dezgeg/nix,acowley/nix,layus/nix,peti/nix,joelmo/nix,bennofs/nix,garbas/nix,NixOS/nix,peti/nix