Consider Adding PR paper

[TonyPod]

Hi Xialei Liu,

Thank you for maintaining such a great repo for continual learning literature!

Could you please add the following paper that was published in PR 2024

Paper: Introspective GAN: Learning to Grow a GAN for Incremental Generation and Classification

Url: https://www.sciencedirect.com/science/article/abs/pii/S0031320324001341

Code: https://github.com/TonyPod/IntroGAN

Thanks for your consideration!