You can add descriptions to Todoist projects.

These can contain any text and links you want to have easy access to when working on the project.

Just go to the project, add a task, and make sure the task’s name starts with an asterisk followed by a space such as “* my example task”.

The complicated name for this is “uncompletable tasks”, but never mind that.

I use these to link to websites with information relevant for the current project or link to my Obisidian note for the project. Anything that’s not a “do this thing” but rather just relevant when working on the project.