fix: <main> element on all pages

this is an accessibility best practice, we had <div id=main> but
needed to use either <main> or role=main, using the element works

Author: phette23

_layouts/color-test.html

@@ -1,8 +1,8 @@
 {% include header.html %}
 {% include search_results.html %}
 
-<div class="CT-body" id="main">
+<main class="CT-body" id="main">
 {{ content }}
-</div>
+</main>
 
 {% include footer.html %}

_layouts/day-menu.html

@@ -2,7 +2,7 @@
 {% include search_results.html %}
 
 {% assign menu = site.data[page.menu] %}
-<div id="main">{% comment %} #main element needed for skip-menu link but we can't add it inside the loop {% endcomment %}</div>
+<main id="main">{% comment %} #main element needed for skip-menu link but we can't add it inside the loop {% endcomment %}</main>
 {% for meal in menu %}
 <section>
     <div class="container">

_layouts/day-schedule.html

@@ -1,7 +1,7 @@
 {% include header.html %}
 {% include search_results.html %}
 
-<div class="container" id="main">
+<main class="container" id="main">
     <div class="row">
         <div class="col-12">
             <h1>{% assign day = page.day | slice: -1 %}
@@ -24,6 +24,6 @@ <h1>{% assign day = page.day | slice: -1 %}
             {% endif %}
         </div>
     </div>
-</div>
+</main>
 
 {% include footer.html %}

_layouts/default.html

@@ -1,6 +1,6 @@
 {% include header.html %}
 {% include search_results.html %}
-<div id="main" class="content">
+<main id="main" class="content">
 {{ content }}
-</div>
+</main>
 {% include footer.html %}

_layouts/presentation.html

@@ -17,7 +17,7 @@
 {% endif %}
 
 <script src="{{ "/assets/js/placeholder.js" | relative_url }}"></script>
-<div class="container presentation" id="main">
+<main class="container presentation" id="main">
     <div class="row">
         <div class="col-12 col-sm-8 col-md-9">
 
@@ -204,6 +204,6 @@ <h2>Location</h2>
             {% endif %}
         </div>
     </div>
-</div>
+</main>
 
 {% include footer.html %}

_layouts/secondary-nav.html

@@ -33,9 +33,9 @@
                     </ul>
                 </nav>
             </div>
-            <div id="main" class="col-12 col-md-9 col-lg-10">
+            <main id="main" class="col-12 col-md-9 col-lg-10">
                 {{ content }}
-            </div>
+            </main>
         </div>
     </div>
 </section>