Oh I'm sure there'll be plenty of map editor related posts here shortly, people just need to test the actual game first. I've played the beta so much and always pined for the editor once the release came, so I'm testing the hell out of that now.

As for your question, the editor file is called 'Editor.exe', and is located in the same folder as the game executable. Depending on whether you got the game via Ubistore (or any other store) or Steam, just find the folder where the game executable is. Open up the properties of the game shortcut, and you should easily find the path to it there.
Cheers and happy map creating!