feat(settings): Change permissions tab to 2 column layout

It collapses to single column for slim viewports.

src/html/settings.html

@@ -173,7 +173,8 @@ <h3>Danger Zone</h3>
         </div>
         <div class="tab tab-3">
           <div class="section">
-            <h2>Url Permissions</h2>
+            <h2>Integrations</h2>
+            <p>Enable the tools you want to use with Toggl Button. You can enable everything by clicking the "Enable all" button.</p>
             <div class="permissions-toolbar" data-id="regular">
               <input type="text" id="permission-filter" placeholder="Filter permissions"/>
               <a href="javascript:void(0)" id="filter-clear">&times;</a>
@@ -183,13 +184,12 @@ <h2>Url Permissions</h2>
               </div>
             </div>
             <div id="perm-container"></div>
-            <p class="description">Enable tools you want to use with Toggl Button. You can enable all by clicking "Enable all" button in the top.</p>
           </div>
 
           <div class="section">
-            <h2>Custom Domain Url Permissions</h2>
+            <h2>Custom Integrations</h2>
+            <p>If you use a tool hosted on a custom domain, you can enable it here. Enter the domain name in the format "toggl.com" and select the integration from the dropdown. <em>Ports are not supported.</em></p>
             <input type="text" id="new-permission" placeholder="Custom domain url"/>
-            <p class="description">Define custom domains here. Just type in the domain name without http(s) in format "toggl.com" and select the integration from dropdown. Ports are currently not supported.</p>
             <div class="button-container">
                 <div id="origins-container"></div>
                 <button id="add-permission">Add</button>

src/styles/settings.css

@@ -48,7 +48,13 @@ input[type='number'] {
 }
 
 .tab.active {
-  display: block;
+  display: flex;
+}
+
+@media (max-width: 860px) {
+  .tab.active {
+    display: block;
+  }
 }
 
 .list {
@@ -175,7 +181,7 @@ header li:hover {
 }
 
 .section {
-  width: 400px;
+  flex: 1;
 }
 
 .section:hover .description {