Release of HLA prediction model

[jalew188]

We do not release the HLA prediction model in alphapeptdeep code base, to make alphapeptdeep more generic on DL framework and library prediction for common users.

Instead, we plan to create a new repository to release HLA prediction code as well as the models. This will be done soon as alphapeptdeep becomes more stable. Once it is done, we will update the link of the repository here.

[jalew188]

HLA prediction model is now in https://github.com/MannLabs/PeptDeep-HLA