### Bug description

[Minimal Reproducible Example](https://github.com/quarto-dev/quarto-cli/files/11230763/citable-articles-page-layout-custom.zip)

When using [custom page layout](https://quarto.org/docs/output-formats/page-layout.html#page-layout) in `_quarto.yml` like

```
format: 
  html:
    page-layout: custom
```

the [citable article information](https://quarto.org/docs/authoring/create-citeable-articles.html) is not displayed.

## Observed Output

Citable article information is **not** present.

![Screenshot 2023-04-14 at 10-39-57 MWE - Minimal Example](https://user-images.githubusercontent.com/1506457/231993097-27719f8e-cb3b-403c-b034-5346be48f9f2.png)

## Expected Output

Citable article information is present as when using `page-layout: full` or `page-layout: article`.

![Screenshot 2023-04-14 at 10-39-24 MWE - Minimal Example](https://user-images.githubusercontent.com/1506457/231993132-08e59908-edc7-45e9-b90e-b9107e424f3c.png)

## Environment

Output of `quarto check`:

```
[✓] Checking versions of quarto binary dependencies...
      Pandoc version 3.1.1: OK
      Dart Sass version 1.55.0: OK
[✓] Checking versions of quarto dependencies......OK
[✓] Checking Quarto installation......OK
      Version: 1.3.324
      Path: /opt/quarto/bin

[✓] Checking basic markdown render....OK

[✓] Checking Python 3 installation....OK
      Version: 3.10.6
      Path: /usr/bin/python3
      Jupyter: 5.2.0
      Kernels: python3

(-) Checking Jupyter engine render....Traceback (most recent call last):
  File "/opt/quarto/share/jupyter/jupyter.py", line 21, in <module>
    from notebook import notebook_execute, RestartKernel
  File "/opt/quarto/share/jupyter/notebook.py", line 18, in <module>
    from nbclient import NotebookClient
ModuleNotFoundError: No module named 'nbclient'
[✓] Checking Jupyter engine render....OK
```

### Checklist

- [X] Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
- [X] Please [format your issue](https://quarto.org/bug-reports.html#formatting-make-githubs-markdown-work-for-us) so it is easier for us to read the bug report.
- [X] Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [X] Please document the operating system you're running. If on Linux, please provide the specific distribution.
- [X] Please provide the output of `quarto check` so we know which version of quarto and its dependencies you're running.
dragonstyle
2023-04-14T08:49:44Z
rgaiacs
bug
v1.4
closed
Citeable Articles not supported in page-layout: custom
https://github.com/quarto-dev/quarto-cli/issues/5189