Add form attribute to settings page inputs

assets/javascripts/templates/pages/settings_tmpl.coffee

@@ -6,13 +6,13 @@ app.templates.settingsPage = (settings) -> """
 
     <div class="_settings-inputs">
       <label class="_settings-label">
-        <input type="checkbox" name="dark" value="1"#{if settings.dark then ' checked' else ''}>Enable dark theme
+        <input type="checkbox" form="settings" name="dark" value="1"#{if settings.dark then ' checked' else ''}>Enable dark theme
       </label>
       <label class="_settings-label _setting-max-width">
-        <input type="checkbox" name="layout" value="_max-width"#{if settings['_max-width'] then ' checked' else ''}>Enable fixed-width layout
+        <input type="checkbox" form="settings" name="layout" value="_max-width"#{if settings['_max-width'] then ' checked' else ''}>Enable fixed-width layout
       </label>
       <label class="_settings-label _hide-on-mobile">
-        <input type="checkbox" name="layout" value="_sidebar-hidden"#{if settings['_sidebar-hidden'] then ' checked' else ''}>Automatically hide and show the sidebar
+        <input type="checkbox" form="settings" name="layout" value="_sidebar-hidden"#{if settings['_sidebar-hidden'] then ' checked' else ''}>Automatically hide and show the sidebar
         <small>Tip: drag the edge of the sidebar to resize it.</small>
       </label>
     </div>
@@ -23,10 +23,10 @@ app.templates.settingsPage = (settings) -> """
 
     <div class="_settings-inputs">
       <label class="_settings-label">
-        <input type="checkbox" name="smoothScroll" value="1"#{if settings.smoothScroll then ' checked' else ''}>Use smooth scrolling
+        <input type="checkbox" form="settings" name="smoothScroll" value="1"#{if settings.smoothScroll then ' checked' else ''}>Use smooth scrolling
       </label>
       <label class="_settings-label">
-        <input type="checkbox" name="arrowScroll" value="1"#{if settings.arrowScroll then ' checked' else ''}>Use arrow keys to scroll the main content area
+        <input type="checkbox" form="settings" name="arrowScroll" value="1"#{if settings.arrowScroll then ' checked' else ''}>Use arrow keys to scroll the main content area
         <small>With this checked, use <code class="_label">alt</code> + <code class="_label">&uarr;</code><code class="_label">&darr;</code><code class="_label">&larr;</code><code class="_label">&rarr;</code> to navigate the sidebar.</small>
       </label>
     </div>