How can I split the text in the navigation bar into two rows in the _site.yml file when creating a website using R Markdown

I am working on building a simple website through R markdown. And below is my _site.yml file:

name: "SampleWeb"
navbar:
  title: "SampleWeb"
  left:
    - text: "Home"
      href: index.html
    - text: "Descriptive Analysis"
      href: descriptive_analysis.html
    - text: "Baseline GWAS Covariate-Sex"
      href: gwas_baseline.html

My question is how to split the "Baseline GWAS Covariate-Sex" into two rows after build the website.

I tried "Baseline GWAS\nCovariate-Sex" and "Baseline GWAS
Covariate-Sex", but neither of these two approaches works. What should I try next? Any help is appreciated!

As you are dealing with HTML you have to use a <br> tag to add a line break. However, simply adding a <br> tag to the _site.yml will not work as it gets escaped and hence rendered as text.

I haven't found an option to prevent that. But following R Markdown: The Definitve Guide one option to achieve your desired result would be to use a _navbar.html file which allows for more control of the navbar.

# Modified from https://github.com/rstudio/rmarkdown-website/blob/master/_navbar.html
<div class="navbar navbar-default  navbar-fixed-top" role="navigation">
  <div class="container">
    <div class="navbar-header">
      <!-- NOTE: add "navbar-inverse" class for an alternate navbar background -->
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar">
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" href="index.html">SampleWeb</a>
    </div>
    <div id="navbar" class="navbar-collapse collapse">
      <ul class="nav navbar-nav">
        <li><a href="index.html">Home</a></li>
        <li><a href="descriptive_analysis.html">Descriptive Analysis</a></li>
        <li><a href="gwas_baseline.html">Baseline GWAS<br>Covariate-Sex</a></li>
      </ul>
    </div><!--/.nav-collapse -->
  </div><!--/.container -->
</div><!--/.navbar -->