Addon-Docs: Props of subcomponents are not indexed

Describe the bug With the current Storybook 6 RC 8 I want to display the props of my subcomponents within the MDX files. In the beta I did this using <Props components={{ProjectOverview, ProjectOverviewEntry, ProjectOverviewProgress}} />, but in RC this seems to be impossible. I only get the props of the main component displayed. So I can even omit components={{}}, I still get the props of the main component when I note <props /> in the MDX file.

Expected behavior Representation of the props of the main and sub components.

Code snippets Example Documentation with MDX (Vue)

import { Meta, Story, Props, Preview } from '@storybook/addon-docs/blocks'
import ProjectOverview from './ProjectOverview.vue'
import ProjectOverviewEntry from './ProjectOverviewEntry.vue'
import ProjectOverviewProgress from './ProjectOverviewProgress.vue'

<Meta
  title='Components|component/ProjectOverview'
  component={ ProjectOverview }
/>

export const ProjectOverviewElement = () => ({
  data () {
    return {
      projects: [...]
    }
  },
  components: { ProjectOverview },
  template: `
    <ProjectOverview :projects="projects" />
  `
})

# ProjectOverview

<Preview withToolbar="true">
  <Story name='ProjectOverviewStory'>
    {ProjectOverviewElement.bind({})}
  </Story>
</Preview>

<Props components={{ProjectOverview, ProjectOverviewEntry, ProjectOverviewProgress}} />

System: Environment Info:

System: OS: macOS 10.15.5 CPU: (12) x64 Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz Binaries: Node: 14.4.0 - ~/.nvm/versions/node/v14.4.0/bin/node Yarn: 1.17.3 - /usr/local/bin/yarn npm: 6.14.5 - ~/.nvm/versions/node/v14.4.0/bin/npm Browsers: Chrome: 83.0.4103.116 Firefox: 78.0.2 Safari: 13.1.1 npmPackages: @storybook/addon-a11y: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-actions: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-backgrounds: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-controls: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-docs: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-knobs: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-links: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-storyshots: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-storysource: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addon-viewport: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/addons: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/source-loader: ^6.0.0-rc.8 => 6.0.0-rc.8 @storybook/vue: ^6.0.0-rc.8 => 6.0.0-rc.8

storybookjs / storybook

Addon-Docs: Props of subcomponents are not indexed #11583