The level editor is still experimental, and has a terrible, terrible UI currently (but I'm working on that)
However, if you do make anything you think is good, feel free to copy paste the text file to here.
All the custom levels you make are stored in the PlatFall/PlatFall_Data/CustomLevels folder
They are simple text files, so just copy pasting their contents into here will mean anyone else can make a text file with that in it and put it in that folder to test them in the editor.
Nice.