Minecraft wiki entry for Creating_behavior_packs, associated text: Again, navigate to the development_behavior_packs folder and create there a new folder named "tutorial_behavior_pack":
(%userprofile%\AppData\Local\Packages\Microsoft.MinecraftUWP_8wekyb3d8bbwe\LocalState\games\com.mojang\development_behavior_packs\tutorial_behavior_pack)
Within that new folder create a JSON file called "manifest.json"