TaskPaper mode is a major mode for working with files in TaskPaper
format. The format was invented by Jesse Grosjean and named after his
TaskPaper macOS app <https://www.taskpaper.com>, which is a system
for organizing your outlines and tasks in a text file.

TaskPaper mode is implemented on top of Outline mode. Visibility
cycling and structure editing help to work with the outline
structure. Special commands also provided for tags manipulation,
sorting, querying, refiling, and archiving of items.