Slugify tag and category links (alshedivat#947)

Fixes links to jekyll-archive pages when tag/category contains spaces.

Author: sim642

_layouts/post.html

@@ -23,15 +23,15 @@ <h1 class="post-title">{{ page.title }}</h1>
       {%- if tags != "" %}
       &nbsp; &middot; &nbsp;
         {% for tag in page.tags -%}
-        <a href="{{ tag | prepend: '/blog/tag/' | prepend: site.baseurl}}">
+        <a href="{{ tag | slugify | prepend: '/blog/tag/' | prepend: site.baseurl}}">
           <i class="fas fa-hashtag fa-sm"></i> {{ tag }}</a> &nbsp;
           {% endfor -%}
       {% endif %}
 
       {%- if categories != "" %}
       &nbsp; &middot; &nbsp;
         {% for category in page.categories -%}
-        <a href="{{ category | prepend: '/blog/category/' | prepend: site.baseurl}}">
+        <a href="{{ category | slugify | prepend: '/blog/category/' | prepend: site.baseurl}}">
           <i class="fas fa-tag fa-sm"></i> {{ category }}</a> &nbsp;
           {% endfor -%}
       {% endif %}

blog/index.html

@@ -25,7 +25,7 @@ <h2>{{ site.blog_description }}</h2>
     <ul class="p-0 m-0">
       {% for tag in site.display_tags %}
         <li>
-          <i class="fas fa-hashtag fa-sm"></i> <a href="{{ tag | prepend: '/blog/tag/' | relative_url }}">{{ tag }}</a>
+          <i class="fas fa-hashtag fa-sm"></i> <a href="{{ tag | slugify | prepend: '/blog/tag/' | relative_url }}">{{ tag }}</a>
         </li>
         {% unless forloop.last %}
           <p>&bull;</p>
@@ -77,15 +77,15 @@ <h3>
           {% if tags != "" %}
           &nbsp; &middot; &nbsp;
             {% for tag in post.tags %}
-            <a href="{{ tag | prepend: '/blog/tag/' | prepend: site.baseurl}}">
+            <a href="{{ tag | slugify | prepend: '/blog/tag/' | prepend: site.baseurl}}">
               <i class="fas fa-hashtag fa-sm"></i> {{ tag }}</a> &nbsp;
               {% endfor %}
           {% endif %}
 
           {% if categories != "" %}
           &nbsp; &middot; &nbsp;
             {% for category in post.categories %}
-            <a href="{{ category | prepend: '/blog/category/' | prepend: site.baseurl}}">
+            <a href="{{ category | slugify | prepend: '/blog/category/' | prepend: site.baseurl}}">
               <i class="fas fa-tag fa-sm"></i> {{ category }}</a> &nbsp;
               {% endfor %}
           {% endif %}