The /docs folder houses all markdown files. The page structure loosely maps to the routing on the site since paths can be changed in the frontmatter.
This folder can also contain components, assets, and whatever else is meant to be versioned when the docusaurus versioning script is run. For example, if there is a page component that is only relevant to the layout section in the current version of Ionic, it could be added to a _components/ folder in docs/layout/. When the versioning script is run, the component will be copied to versioned_docs/version-{X}/layout/_components/ and there will now be a separate component in docs/layout/_components/ that can be deleted or updated to the latest version. The same concept applies to images and other files.
If components are meant to be shared across versions, they can be put in src/components/. If images and other served files are meant to be shared across versions they can be put in static/.
All markdown files in these directories are generated from scripts:
docs/api/docs/cli/commands/docs/native/