StreamTexture and ".stex" format ?¿?

**Your Godot version:**
v3.5.beta1.official [b9b23d222]

**Issue description:**
I don't understand the documentation for "StreamTexture".
Does it mean that only ".stex" files can be loaded into a "StreamTexture" object? I think not.
I recently needed to read the pixels of an image using "get_pixel", someone helped me on discord.
So I had to load the image in a "StreamTexture" object but in the documentation it only talks about those ".stex" files... it confused me, in the documentation it doesn't indicate anything that ".png" files can be loaded in "StreamTexture" objects ".

Could it be stated in the documentation for "StreamTexture" that it can also be used to load other formats like ".png"?
**URL to the documentation page (if already existing):**
https://docs.godotengine.org/en/3.5/classes/class_streamtexture.html