fix submit button type for ComingSoon theme (#13868)

Author: derandre84

src/OrchardCore.Themes/TheComingSoonTheme/Recipes/Snippets/Widget__Register.liquid

@@ -2,6 +2,6 @@
     {{ Model.ContentItem.Content.HtmlBodyPart.Html | raw }}
     <div class="input-group input-group-newsletter">
         <input name="{{ Model.ContentItem.Content.Register.InputFieldName.Text }}" class="form-control" aria-describedby="submit-button" aria-label="{{ Model.ContentItem.Content.Register.Placeholder.Text }}" type="email" placeholder="{{ Model.ContentItem.Content.Register.Placeholder.Text }}"/>
-        <button class="btn btn-primary" id="submit-button" type="button">{{ Model.ContentItem.Content.Register.Button.Text }}</button>
+        <button class="btn btn-primary" id="submit-button" type="submit">{{ Model.ContentItem.Content.Register.Button.Text }}</button>
     </div>
-</div>
+</div>