Remove Internet Explorer leftovers

site/layouts/_default/404.html

@@ -8,7 +8,7 @@
 
     {{ partial "docs-navbar" . }}
 
-    <main class="my-auto p-5" id="content" role="main">
+    <main class="my-auto p-5" id="content">
       {{ .Content }}
     </main>
 

site/layouts/_default/docs.html

@@ -15,7 +15,7 @@
           {{ partial "docs-sidebar" . }}
         </div>
 
-        <main class="col-md-9 py-md-3 pl-md-5 bd-content" role="main">
+        <main class="col-md-9 py-md-3 pl-md-5 bd-content">
           <h1 class="bd-title" id="content">{{ .Title | markdownify }}</h1>
           <p class="bd-lead">{{ .Page.Params.Description | markdownify }}</p>
           {{ partial "ads" . }}

site/layouts/_default/single.html

@@ -19,7 +19,7 @@
       </div>
     </header>
 
-    <main class="bd-content py-5" id="content" role="main">
+    <main class="bd-content py-5" id="content">
       <div class="container">
         {{ .Content }}
       </div>

site/layouts/partials/callout-warning-input-support.md

@@ -1,3 +1,3 @@
 ##### Date & color input support
 
-Keep in mind date inputs are [not fully supported](https://caniuse.com/#feat=input-datetime) by IE and Safari. Color inputs also [lack support](https://caniuse.com/#feat=input-color) on IE.
+Keep in mind date inputs are [not fully supported](https://caniuse.com/#feat=input-datetime) by all browsers, namely Safari.

site/layouts/partials/home/masthead.html

@@ -1,4 +1,4 @@
-<main class="bd-masthead mb-3 mb-md-5 border-bottom" id="content" role="main">
+<main class="bd-masthead mb-3 mb-md-5 border-bottom" id="content">
   <div class="container">
     <div class="row">
       <div class="col-6 mx-auto col-md-4 order-md-2 col-lg-5">