add evaluation helpers and updated readme

evaluation/evaluation_readme.md

evaluation/helpers/__init__.py

evaluation/helpers/__pycache__/__init__.cpython-39.pyc

evaluation/helpers/__pycache__/inception.cpython-39.pyc

evaluation/helpers/__pycache__/kNN.cpython-39.pyc

evaluation/helpers/__pycache__/metrics.cpython-39.pyc

evaluation/helpers/__pycache__/score_infinity.cpython-39.pyc

evaluation/helpers/__pycache__/vggface.cpython-39.pyc

evaluation/helpers/inception.py

evaluation/helpers/kNN.py

evaluation/helpers/metrics.py

evaluation/helpers/score_infinity.py

evaluation/helpers/vggface.py