extra_navbar and extra_footer ignored

[felixchenier]

Describe the bug

context When I add a string in either/both of extra_navbar and extra_footer, these strings are ignored. The navbar still shows the "Theme by the Executable Book Project" and the footer still shows the copyright line.

expectation Following the documentation, it seems that putting a string in these options would change these default values.

I checked for the obvious problems: I'm editing the good _config.yml (if I put goofy strings with syntax errors, it won't build).

thank you note I added this section to thank you for this wonderful project. I'm currently working on an hybrid book/manual/package and jupyter-book is close to heaven for this.

Reproduce the bug

Here is the contents from my _config.yml file. See that I wrote some junk in extra_navbar and extra_footer, but the result is still the default values, even if I completely wipe the _build folder.

# Book settings
# Learn more at https://jupyterbook.org/customize/config.html

title: Kinetics Toolkit
author: Félix Chénier
copyright: 2020-2022
logo: logo.png

# Force re-execution of notebooks on each build.
# See https://jupyterbook.org/content/execute.html
execute:
  execute_notebooks: cache

html:
  favicon                   : ""  # A path to a favicon image
  use_edit_page_button      : false  # Whether to add an "edit this page" button to pages. If `true`, repository information in repository: must be filled in
  use_fullscreen_button     : false
  use_repository_button     : false  # Whether to add a link to your repository button
  use_issues_button         : false  # Whether to add an "open an issue" button
  use_multitoc_numbering    : true   # Continuous numbering across parts/chapters
  extra_navbar              : "asdasdasd"  # Will be displayed underneath the left navbar.
  extra_footer              : "jknfkjn" # Will be displayed underneath the footer.
  google_analytics_id       : ""  # A GA id that can be used to track book views.
  home_page_in_navbar       : true  # Whether to include your home page in the left Navigation Bar
  baseurl                   : "https://kineticstoolkit.uqam.ca/doc/"  # The base URL where your book will be hosted. Used for creating image previews and social links. e.g.: https://mypage.com/mybook/
  comments:
    hypothesis              : false
    utterances              : false
  

parse:
  myst_substitutions:
    "stub": |
      ```{admonition} Section in development
      :class: admonition-stub
      This section is still in heavy development. Your [suggestions](dev_contributing.md) are welcome.
      ```
    "incomplete": |
      ```{admonition} Incomplete section
      Some elements of this section are incomplete or out of date. Please feel free to [contribute](dev_contributing.md).
      ```
    "dev": |    
      ```{warning}
      This section refers to unstable code. This code may not be tested, and the whole API and behaviour is expected to change in the future. Do not use this code for your research.
      ```


sphinx:
  extra_extensions:
  - 'sphinx.ext.autodoc'     # Document objects using docstrings in API
  - 'sphinx.ext.autosummary' # Generate summary table pages (for autodoc)
  - 'sphinx.ext.napoleon'    # Parse numpy-style docstrings (for autodoc)
  - 'sphinx.ext.viewcode'
  - 'myst_nb'
  - 'custom-directives'
  - 'sphinx_sitemap'

  config:
    html_baseurl: 'https://kineticstoolkit.uqam.ca/doc'
    add_module_names: False
    autosummary_generate: True
    autodoc_typehints: description
    autodoc_type_aliases:
        'ArrayLike': 'ArrayLike'
        'TimeSeries': 'TimeSeries'
    napoleon_google_docstring: False
    napoleon_numpy_docstring: True
    napoleon_include_init_with_doc: False
    napoleon_include_private_with_doc: False
    napoleon_include_special_with_doc: False
    napoleon_use_admonition_for_examples: False
    napoleon_use_admonition_for_notes: True
    napoleon_use_admonition_for_references: True
    napoleon_use_ivar: False
    napoleon_use_param: True
    napoleon_use_rtype: True
    templates_path: ['_templates']
    html_favicon: favicon.ico
    exclude_patterns:
      - '_build'
      - 'Thumbs.db'
      - '.DS_Store'
      - '.ipynb_checkpoints'
      - 'api/external.*'
      - 'api/ktk.external.*'
      - 'api/ktk.pushrimkinetics*'
      - 'toc.md'
      - '_templates'

    html_theme_options:
      'logo_only': True  # default False
      'collapse_navigation': True
      'navigation_depth': 4

List your environment

Jupyter Book      : 0.13.1
External ToC      : 0.2.4
MyST-Parser       : 0.15.2
MyST-NB           : 0.13.2
Sphinx Book Theme : 0.3.3
Jupyter-Cache     : 0.4.3
NbClient          : 0.5.13

Installed from conda-forge on a macOS system.