Absolutely.
When you create a game with Unity you don't transfer any rights to any of your copyrighted material (or others' material that you are licensed to use) to Unity, nor do you give up any of those rights. So you are still free to do whatever you want with all of that.
As long as you don't store anything of Unity's (or anyone else's) that you are not licensed to use and redistribute, you'll be fine. For example if you were to have somehow obtained a valid source license to Unity's internals, that license would likely prohibit you from redistributing that source to the public.
But anything that's yours or that you have a license for, you're fine.
This is documented, as noted by @UnholySheep in the comments, in both the overview page and the TOS.