docs: release notes for the v12.0.0-rc.2 release
docs: release notes for the v12.0.0-rc.2 release

mgechev/angular,brandonroberts/angular,brandonroberts/angular,brandonroberts/angular,angular/angular,brandonroberts/angular,gnomeontherun/angular,angular/angular,gnomeontherun/angular,angular/angular,manekinekko/angular,shairez/angular,manekinekko/angular,manekinekko/angular,angular-indonesia/angular,brandonroberts/angular,shairez/angular,angular/angular,ocombe/angular,gkalpak/angular,shairez/angular,brandonroberts/angular,mgechev/angular,gnomeontherun/angular,manekinekko/angular,mgechev/angular,JiaLiPassion/angular,ocombe/angular,angular-indonesia/angular,angular-indonesia/angular,JiaLiPassion/angular,angular-indonesia/angular,ocombe/angular,shairez/angular,manekinekko/angular,gkalpak/angular,mgechev/angular,ocombe/angular,ocombe/angular,JiaLiPassion/angular,JiaLiPassion/angular,gnomeontherun/angular,ocombe/angular,manekinekko/angular,mgechev/angular,gkalpak/angular,shairez/angular,gkalpak/angular