Participant contributions are done in many forms, from improving prompts, to helping build community around the collabathon. However, a big part of your contributions is going to involve your actual 'hacks' and work that you want to submit in an official manner.
The official way to submit your work as it relates to a specific 'Prompt Task' is through the CoMakery space. In CoMakery, Prompts are called 'Projects' and they hold internal 'Batch of Tasks' and 'Tasks.' If you are working on those tasks then you need to click 'Start Task.' Once you are ready to submit, you will be able to upload a URL and comments of your work, unless a specific URL is specified for that tasks. Approved submissions will award you with collabathon tokens, which you can collect to build your reputation. See the image below as reference for this submission process:
Most likely if the prompt tasks are code related, then it will prompt you to submit a GitHub link, unless its specifically related to code development within the versions of the Open Climate platform, either in the repository of the demo version, or in the alpha version being developed, in which case it will show up as an issue, or provide specific details of where to submit.
Otherwise, all code work can be added to Collabathon repository in GitHub. To do this, you will need to Fork the repository, create a branch (unless your content is standalone), and then submit a pull request. Please load your Hacks into the 'HACKS' folder.
This GitBook has a special section on the side bar called HACKS where you and your team can create a special page to upload your work and its documentation. You can embed here google docs, google slides, images, text, code, API documentation etc. So definitely this GitBook is the best place to contribute your rich documentation.
Use the spreadsheet below to register your team, participants and the prompts you are working on. This will help identify everyone on your team, not just the person submitting the forms.