The way to do it hasn't changed.

you have to go through the steam website now to do that not the steam app according to steam its not secure to do it through the app

Steam do not provide cloud storage for your video's, you can record and export, then upload to youtube and then share to steam from the tube. If they did provide that it would be ridiculously expensive and they would have to display ads to counter the shear cost of storage and bandwidth whilst upgrading to massive datacentres.

They have given us a built in tool to record our gameplay and edit and export whenever we want, that will do most of us fine, means i don't need to run another program in the background to do that.