Front-matter 'polyglot' param for polyglot pages. Closes cucumber#8

CONTRIBUTING.md

@@ -13,3 +13,42 @@ body - do not use `#` headers as we only want a single `h1` header per page.
 Start the body with a paragraph, not a header. If you start with a header, the
 top of the page will have a `h1` followed immediately by a `h2`, which does not
 look good.
+
+## Polyglot pages
+
+All pages with source code should be polyglot, meaning there should be source code
+for all supported programming languages. See `themes/cucumber-hugo/layouts/partials/language-tabs.html`
+for a list of supported languages.
+
+The front-matter should also declare that this is a polyglot page so that the
+programming language tabs are displayed at the top of the page:
+
+```yaml
+polyglot: true
+```
+
+When a tab is selected, only source code and language-specific text for the selected
+language will be displayed.
+
+### Source code
+
+Use fenced code blocks to specify polyglot source code:
+
+    ```ruby
+    puts "hello"
+    ```
+
+    ```javascript
+    console.log("hello")
+    ```
+
+    ```java
+    System.out.println("hello")
+    ```
+
+### Language-specific text
+
+Use the `{{% text %}}` shortcode around text that should only be displayed for
+a particular programming language:
+
+    The preferred build tool is {{% text "java" %}}Rake{{% /text %}}{{% text "java" %}}Yarn{{% /text %}}{{% text "java" %}}Maven{{% /text %}}.

content/cucumber/Step-Definitions-Orig.md

@@ -1,6 +1,7 @@
 ---
 menu: gherkin
 title: Step Definitions Orig
+polyglot: true
 ---
 
 When Cucumber executes a step in a scenario it will look for a matching *step definition* to execute.

themes/cucumber-hugo/layouts/_default/single.html

@@ -1,5 +1,4 @@
 {{ partial "header.html" . }}
 {{ partial "nav.html" . }}
-{{ partial "language-nav.html" . }}
 {{ partial "menu-content" . }}
 {{ partial "footer.html" . }}

themes/cucumber-hugo/layouts/partials/language-tabs.html

@@ -0,0 +1,22 @@
+<div class="tabs is-boxed is-right">
+  <ul>
+    <li data-language="java">
+      <a>
+        <span class="icon is-small"><i class="devicon-java-plain colored"></i></span>
+        <span>Java</span>
+      </a>
+    </li>
+    <li data-language="javascript">
+      <a>
+        <span class="icon is-small"><i class="devicon-javascript-plain colored"></i></span>
+        <span>JavaScript</span>
+      </a>
+    </li>
+    <li data-language="ruby">
+      <a>
+        <span class="icon is-small"><i class="devicon-ruby-plain colored"></i></span>
+        <span>Ruby</span>
+      </a>
+    </li>
+  </ul>
+</div>

themes/cucumber-hugo/layouts/partials/menu-content.html

@@ -5,6 +5,9 @@
         {{ partial "menu.html" . }}
       </div>
       <div class="column is-three-quarters">
+        {{ if eq .Page.Params.polyglot true }}
+          {{ partial "language-tabs.html" . }}
+        {{ end }}
         <div class="content">
           <h1>{{ .Title }}</h1>
           {{ .Content }}