Today, the vast literature of programming language theory is complemented by a large body of work on text editors for programming languages such as pretty printing, linting, or structured editing. Yet, both document languages and document editors are understudied in the literature, meaning that the rich landscape of document languages and editors lack a theoretical framework to construct and evaluate them, as well as understand their semantics. Recent work on a core document calculus by Crichton and Krishnamurthi motivates a new line of research on document languages by pointing out their ubiquity, demonstrating the connections between document languages and programming languages, and providing a formalization of the document language semantics. In this research, inspired by works such as Hazel on program editors, we propose Tail, a typed and structured document editor and language for constructing and manipulating document templates. This extended abstract introduces a model of templates as partial documents, a refinement relation on partial documents, and builds up the Tail editor on top of the provided refinement relation. The paper is concluded with the current state of the project followed by a brief discussion of future directions.