put onnx to tflite conversion behind flag in training code

Merge pull request #289 from dscripka/python_version_increase

bump workflow python versions

Bump python version to 3.10+, switch tflite to new ai-edge-litert

Remove outdated colab link.

Merge pull request #179 from mikejgray/fix/custom-verifier-type-hints

fix: custom verifier type hints

fixed bug in train.py when using longer training examples than normal [skip ci]

missing slash [skip ci]

fix link for audioset data

Update README.md [skip ci]

fixed typo in error message

Update README.md [skip ci]

updated Readme for release [skip ci]

fix version [skip ci]