Howdy from Rowdy!
ok, so I was fiddling today and I finally figured how to change the homepage of the steam ingame browser in the game overlay! now I realise some people will say.......errr hurrr durrr! but this is fooor those who didn't know
here is how!
go to your friends list and click chane profile name as in picture V
on the next page click on the in-game tab and voila! its at the bottom!!! V
now the steampowered site will still open when u go into the browser but click the + to open a new tab and it opens the page you put in there!
GLHF