Surf the internet for a couple of minutes and check out the data repositories mentioned above: Figshare, Zenodo, Dryad. Others like OpenDataRepository are also a popular choice. Depending on your field of research, you might find community-recognized repositories that are well-known in your field, especially by looking at journal recommendations. You might also find useful these data repositories recommended by Nature. Discuss with your neighbor which data repository you might want to approach for your current project and explain why.
Large data or image files such as .md5 or .psd file types can be tracked within
a github repository using the Git Large File Storage
open source extension tool. This tool automatically uploads large file contents to
a remote server and replaces the file with a text pointer within the github repository.
Try downloading and installing the Git Large File Storage extension tool, then add tracking of a large file to your github repository. Ask a colleague to clone your repository and describe what they see when they access that large file.