Pinning the entire document library is supported today. Learn more here, https://support.microsoft.com/en-us/office/add-a-sharepoint-page-or-list-to-a-channel-in-teams-131edef1-455f-4c67-a8ce-efa2ebf25f0b.
We currently do not support pinning a specific folder, but we are considering this feature.
An error occurred while saving the commentAmanda commented
Lists are my favorite part of SharePoint! I want my list to be viewable in Teams (but not editable). My Team site is for our IT procurement. We manage our invoices, contracts, and budget information there. I want my Vendor Information list to be a Tab so that we have ready access to our contact people, contract #s and billing details. It would be one stop shopping for all of our IT procurement needs.