Describe the feature

Basically a 1 block tall door, or a trapdoor that opens sideways.

Simple addition, will be added for the next version after 5.6.0/6.3.0 respectively.
I just have to think of a good name :D

Probably gate would be fine.
And in terms of implementation, I hope it'll be versatile like trapdoor (doesn't require a block support/can float)
Thanks!

Gate sounds good, I'll go with that.
I'll make sure to keep it simple and unrestricted