Updated home page tags to headings

• Updated:
- home page tags to headings

app/views/about/_registration.html.haml

@@ -1,6 +1,6 @@
 = simple_form_for(new_user, url: user_registration_path) do |f|
   .simple_form__overlay-area
-    %p.lead= t('about.federation_hint_html', instance: content_tag(:strong, site_hostname))
+    %h2.lead= t('about.federation_hint_html', instance: content_tag(:strong, site_hostname))
 
     .fields-group
       = f.simple_fields_for :account do |account_fields|

app/views/about/show.html.haml

@@ -11,7 +11,7 @@
       .landing__brand
         = link_to root_url, class: 'brand' do
           %img(src='/legacy/gab_logo.svg' alt='Gab Social')
-        %span.brand__tagline=t 'about.tagline'
+        %h1.brand__tagline=t 'about.tagline'
 
     .landing-columns--right
       .box-widget