[AIT] Adaptive Image Transformer for One-Shot Object Detection

{Multi-head Co-Attention - MCA; Adaptive Image Transformer - AIT; Selective Channel Attention - SCA}

Paper: https://openaccess.thecvf.com/content/CVPR2021/html/Chen_Adaptive_Image_Transformer_for_One-Shot_Object_Detection_CVPR_2021_paper.html?ref=https://githubhelp.com