Initial model update

The initial model has been scaled properly and more models have been added to the engine:
-Boom Box
-Fish
-Milk Truck

Release 1: Basic

This release features the basic properties for the intended 3D engine:

• Movement, rotation and manual orbiting.
• Textur and model loading.
• Drag and drop functionality for models.
• Separate ImGui windows for the models' and the camera's properties.