This is something I've wanted to add for a while now. Quivers will allow you to store up to 20 arrows. This means that you will no longer need an inventory full of arrows.
To make a quiver, you either need Rabbit Fur or Bear Fur (found by skinning rabbits/bears). You will then need to combine one of these with Leather (see this for a guide on obtaining leather).
From there all you need to do is equip your quiver. Of course, you can only have one quiver equipped at a time.
Next up: multiplayer fixes, changes, additions, etc.