I am looking to a way to have a default structure of each document created in Polarion. Right now it's just a blank document, but I would like all documents to have the same layout/headers/sections in the same order.
I have tried looking through polarion documentation but I can only find information on project templates which seem to be related to what links can be setup and what sections exist already.
Polarion does not have a templating function for Live Docs.
A workaround using the UI: create a Project/Space that contains the templates, and sending the users there, for example using a button linking to the template, to manually copy a template into their target Project and Space where the document is to be created. See instructions here: https://polarion.plm.automation.siemens.com/tutorials/reusing-documents
You could develop a small Polarion Java Extension that would do this automatically at the press of a button. For example a servlet that shows a list of available templates, and creates a copy of a template for you. See the Polarion SDK documentation under /Polarion/polarion/SDK/doc for how to create a servlet.
Polarion has a feature though for new Work Items to be pre-filled with content from a "template Work Item", see https://docs.plm.automation.siemens.com/content/polarion/20/help/en_US/user_and_administration_help/administrators_guide/configure_work_items/define_template_work_items.html