Move scripts in a separated folder for clarity

navipy/arenatools/patterns.py

navipy/maths/quaternion.py

navipy/scripts/__init__.py

navipy/scripts/blend_alongtraj.py

navipy/scripts/blend_ongrid.py

navipy/scripts/blend_overlaytraj.py

navipy/scripts/blendnavipy.py

navipy/scripts/blendunittest.py

navipy/sensors/renderer.py

setup.py

tutorials/02-recording-animal-trajectory.ipynb

tutorials/03-rendering-along-trajectory.ipynb