The index of your documentation may be provided in three ways: two are explicit and one is automatic.
sources will be scanned and automatically indexed, unless marked with the noindex frontmatter.The name of the file is important as it contains a pattern to distinguish the chapter/section. Chapters are not required if all sections are to fit in one chapter.
{chapter}--{section}.md
This is the method that stems from the Drupal advanced help module and looks something like this. It is explicit, yet gives the lesser control as the input keys are limited.
[_tasklist]
title = "My Tasklist"
It relies on a json file to provide the outline for your book. Please refer to examples/outline.json for the file schema.
This is the best method for providing exact control as it's completely explicit. That said, it's tedius to maintain and so the other files below should be understood before you commit to using outline.json.
This file is generated during compile IF outline.json is not found in the source directory. It is based on the file structure of source plus other meta data (frontmatter, markdown header detection, etc.) as able to be determined during compile. You will find the file at core/cache/outline.auto.json.
This file will be used during compile to override any values normally visible in outline.auto.json. Use this to override or add to what normally shows up in outline.auto.json. It will have no effect if outline.json is present in the source directory.