docs: update changelog with recent changes and 1.5.2 release.
docs: update changelog with recent changes and 1.5.2 release.

hackerkid/zulip,brainwane/zulip,tommyip/zulip,zulip/zulip,brainwane/zulip,vabs22/zulip,brockwhittaker/zulip,punchagan/zulip,showell/zulip,timabbott/zulip,amanharitsh123/zulip,synicalsyntax/zulip,zulip/zulip,verma-varsha/zulip,synicalsyntax/zulip,punchagan/zulip,jrowan/zulip,vaidap/zulip,eeshangarg/zulip,punchagan/zulip,zulip/zulip,eeshangarg/zulip,Galexrt/zulip,shubhamdhama/zulip,shubhamdhama/zulip,vabs22/zulip,vabs22/zulip,hackerkid/zulip,Galexrt/zulip,amanharitsh123/zulip,jackrzhang/zulip,showell/zulip,punchagan/zulip,rishig/zulip,amanharitsh123/zulip,hackerkid/zulip,dhcrzf/zulip,brockwhittaker/zulip,jrowan/zulip,jackrzhang/zulip,showell/zulip,amanharitsh123/zulip,synicalsyntax/zulip,rht/zulip,andersk/zulip,vaidap/zulip,tommyip/zulip,vaidap/zulip,rishig/zulip,zulip/zulip,hackerkid/zulip,jackrzhang/zulip,tommyip/zulip,Galexrt/zulip,jackrzhang/zulip,eeshangarg/zulip,synicalsyntax/zulip,brainwane/zulip,tommyip/zulip,timabbott/zulip,dhcrzf/zulip,verma-varsha/zulip,eeshangarg/zulip,vabs22/zulip,Galexrt/zulip,kou/zulip,Galexrt/zulip,jrowan/zulip,jrowan/zulip,rht/zulip,vaidap/zulip,timabbott/zulip,synicalsyntax/zulip,brainwane/zulip,zulip/zulip,andersk/zulip,jrowan/zulip,kou/zulip,brainwane/zulip,mahim97/zulip,dhcrzf/zulip,mahim97/zulip,mahim97/zulip,tommyip/zulip,verma-varsha/zulip,jrowan/zulip,hackerkid/zulip,rht/zulip,eeshangarg/zulip,brainwane/zulip,mahim97/zulip,kou/zulip,punchagan/zulip,showell/zulip,vabs22/zulip,rht/zulip,showell/zulip,timabbott/zulip,rht/zulip,jackrzhang/zulip,mahim97/zulip,rishig/zulip,showell/zulip,kou/zulip,eeshangarg/zulip,amanharitsh123/zulip,brockwhittaker/zulip,dhcrzf/zulip,andersk/zulip,dhcrzf/zulip,brockwhittaker/zulip,shubhamdhama/zulip,andersk/zulip,andersk/zulip,eeshangarg/zulip,timabbott/zulip,shubhamdhama/zulip,brainwane/zulip,amanharitsh123/zulip,rishig/zulip,rishig/zulip,rishig/zulip,shubhamdhama/zulip,brockwhittaker/zulip,verma-varsha/zulip,tommyip/zulip,vabs22/zulip,kou/zulip,shubhamdhama/zulip,jackrzhang/zulip,rht/zulip,mahim97/zulip,tommyip/zulip,punchagan/zulip,showell/zulip,zulip/zulip,timabbott/zulip,hackerkid/zulip,zulip/zulip,hackerkid/zulip,rishig/zulip,verma-varsha/zulip,kou/zulip,brockwhittaker/zulip,jackrzhang/zulip,andersk/zulip,shubhamdhama/zulip,dhcrzf/zulip,synicalsyntax/zulip,Galexrt/zulip,andersk/zulip,vaidap/zulip,dhcrzf/zulip,vaidap/zulip,timabbott/zulip,Galexrt/zulip,kou/zulip,verma-varsha/zulip,punchagan/zulip,synicalsyntax/zulip,rht/zulip