Custom collections are empty

I currently have a collection called “projects”, but whenever I put a file in _projects/ it does not seem to show up in the collection. Iterating through the collection does nothing, and going to the links specified by the permalink setting for the collection just returns 404.

My directory structure looks like this:

_includes
  preview.html
_layouts
  default.html
_projects
  test.md
content
  images
    polygradient.png
index.md
blog.md
projects.md
config.yml

This is what _projects/test.md looks like:

test project

This is what projects.md (the page that’s supposed to list all projects) looks like:

---
permalink: /projects/
---
This is where my projects are.
<div class="projects">
  {% for project in site.projects %}
    {% include preview.html %}
  {% endfor %}
</div>

<style>
  .projects {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    grid-gap: 20px;
  }
</style>

And this is my config.yml:

collections:
  projects:
    output: true
    permalink: /projects/:name

nvm. as always, i missed something obvious: my config.yml was config.yml, not _config.yml. great, two hours of pulling my hair out ended up being caused by a typo.

Okay, good. I was just about to ask you for a link to your GitHub repo to take a look at it. Glad it was something simple!