supported optimizer engine for optimization in training

[pavaris-pm]

@rkcosmos I just saw list of optimizers currently supported by EasyOCR for training a custom model, is there any reasons that we have just only these 2 optimizers? if not, i can help making a PR to add more optimizers for more robust model optimization of EasyOCR.

https://github.com/JaidedAI/EasyOCR/blob/c999505ef6b43be1c4ee36aa04ad979175178352/trainer/train.py#L138-L145