Ignore files from collection (hugo _index.md)

I have a hugo site in which I have a content called "project".
My config file:
```
collections:
- name: "project"
editor:
preview: false
label: "Project"
folder: "site/content/project"
create: true
fields:
- {label: "Featured", name: "featured", widget: "boolean", default: false}
- {label: "Title", name: "title", widget: "string"}
- {label: "Publish Date", name: "date", widget: "datetime"}
- {label: "Project Date", name: "project_date", widget: "datetime"}
- {label: "Head Image (Recommended 1920x1080)", name: "head_image", widget: "image", required: false}
- {label: "Thumbnail Image (Recommended 360x560)", name: "thumb_image", widget: "image", required: false}
- {label: "Images", name: "images", widget: list, field:
{label: "Image (Recommended 800x500)", name: "image", widget: "image"}}
- {label: "Description", name: "body", widget: "markdown"}
```

The admin is working fine and I can create/edit my projects. The issue is that the admin also show the _index.md file which is used from hugo for the list page. Also this file has different front-matter (I have a file collection for this to edit from the cms).

**The solution you'd like**
For hugo site should automatically excludes this file from the collection.

**alternatives you've considered**
Maybe a better and more generic solution for all SSGs is to have a [config option](https://www.netlifycms.org/docs/configuration-options/#collections) to let us give an array with some files to be ignored