Correctly slugify distill TOC (#519)

* Correctly slugify distill TOC

* Add special character to demo distill post's TOC

_layouts/distill.html

@@ -73,11 +73,11 @@
           <nav class="l-text figcaption">
           <h3>Contents</h3>
             {% for section in page.toc -%}
-            <div><a href="#{{ section.name | downcase | replace: ' ','-' }}">{{ section.name }}</a></div>
+            <div><a href="#{{ section.name | slugify }}">{{ section.name }}</a></div>
             {% if section.subsections -%}
             <ul>
               {% for subsection in section.subsections -%}
-              <li><a href="#{{ subsection.name | downcase | replace: ' ','-' }}">{{ subsection.name }}</a></li>
+              <li><a href="#{{ subsection.name | slugify }}">{{ subsection.name }}</a></li>
               {% endfor %}
             </ul>
             {%- endif -%}

_posts/2018-12-22-distill.md

@@ -36,7 +36,7 @@ toc:
   - name: Footnotes
   - name: Code Blocks
   - name: Layouts
-  - name: Other Typography
+  - name: Other Typography?
 
 # Below is an example of injecting additional post-specific styles.
 # If you use this post as a template, delete this _styles block.
@@ -173,7 +173,7 @@ It does not interrupt the normal flow of `.l-body` sized text except on mobile s
 
 ***
 
-## Other Typography
+## Other Typography?
 
 Emphasis, aka italics, with *asterisks* (`*asterisks*`) or _underscores_ (`_underscores_`).
 
@@ -279,4 +279,4 @@ Here's a line for us to start with.
 This line is separated from the one above by two newlines, so it will be a *separate paragraph*.
 
 This line is also a separate paragraph, but...
-This line is only separated by a single newline, so it's a separate line in the *same paragraph*.
+This line is only separated by a single newline, so it's a separate line in the *same paragraph*.