title: Using Jekyll's Collection relative_directory for organizing pages/collections
body: <p>I thought that setting the <code>relative_directory</code> <a href="https://jekyllrb.com/docs/collections/#liquid-attributes" rel="noreferrer">(Jekyll Collection Docs)</a> <a href="https://github.com/jekyll/jekyll/pull/3723" rel="noreferrer">(github PR)</a> property being set would help me keep my files organized without compromising my desired output, but it seems to be ignored/not used for producing files. I don't want my collections to be in the root directory, because I find it confusing to have ~10 collection folders adjacent to <code>_assets</code>, <code>_data</code>, <code>_includes</code>, <code>_layouts</code>, and others.</p>
  
  <p>Fixes or alternative solutions are welcomed, as long as long as the output is the same, and my pages are in their own directory, without needing to put <code>permalink</code> front-matter on every single page.</p>
  
  <p><strong>_config.yaml</strong></p>
  
  <pre><code>collections:
    root:
      relative_directory: '_pages/root'
      output: true
      permalink: /:path.html
    root-worthy:
      relative_directory: '_pages/root-worthy'
      output: true
      permalink: /:path.html
    docs:
      relative_directory: '_pages/docs'
      output: true
      permalink: /docs/:path.html
  </code></pre>
  
  <p><strong>Directory Structure:</strong></p>
  
  <pre><code>├── ...
  ├── _layouts
  ├── _pages
  │   ├── root
  │   │   ├── about.html
  │   │   └── contact.html
  │   ├── root_worthy
  │   │   ├── quickstart.html
  │   │   └── seo-worthy-page.html
  │   └── docs
  │       ├── errors.html
  │       └── api.html
  ├── _posts
  └── index.html
  </code></pre>
  
  <p><strong>Desired output:</strong></p>
  
  <pre><code>├── ...
  ├── _site
  │   ├── about.html
  │   ├── contact.html
  │   ├── quickstart.html
  │   ├── seo-worthy-page.html
  │   └── docs
  │       ├── errors.html
  │       └── api.html
  └── ...
  </code></pre>