+MainMenue: Create new Stage files via UI +StageStatic: differentiate between developing and playing

+Added Scenes: MainMenue, LoadingScreen +Stage: Save-Load fuctionality +Sorted Prefabs and Scripts Folder

+Restart: reenabled RestartLevelButton +Level: reenabled Level-completion +FactOrganizer: scetch for dynamic LevelGoals, with-> +FactComparer +ShinyThings: TODO: multiple highlited facts at once

+added Lot&Pendulum-Tool +Using Math3d lib for VectorCalculus +Changed Fact managment (unstable\!) +Misc refactoring

Fixed json-payload for OnLineFacts and LineFacts + Adjustments so that SupplementaryAngles-Scroll works again + Adjusted GET on Scroll/List-endpoint in DisplayScrolls so that it tries several times, because server mostly returns a 500 on first try

Fixed bug occuring when assigning fact during hint-animation + Set default of selected scroll to OppositeLen