Set up Design settings screen

refs https://github.com/TryGhost/Team/issues/1045

- added blank `/settings/design` route and associated screen
  - redirects to settings index if associated labs flag is not enabled
- when custom theme settings labs flag is enabled, replaced Branding and Theme links with single Design link

ghost/admin/app/controllers/design.js

@@ -0,0 +1,4 @@
+import Controller from '@ember/controller';
+
+export default class SettingsDesignController extends Controller {
+}

ghost/admin/app/router.js

@@ -52,6 +52,8 @@ Router.map(function () {
     this.route('settings.members-email', {path: '/settings/members-email'});
     this.route('settings.code-injection', {path: '/settings/code-injection'});
 
+    this.route('settings.design', {path: '/settings/design'});
+
     // this.route('settings.products', {path: '/settings/products'});
     // this.route('settings.product.new', {path: '/settings/product/new'});
     // this.route('settings.product', {path: '/settings/product/:product_id'});

ghost/admin/app/routes/design.js

@@ -0,0 +1,24 @@
+import AuthenticatedRoute from 'ghost-admin/routes/authenticated';
+import {inject as service} from '@ember/service';
+
+export default class DashboardRoute extends AuthenticatedRoute {
+    @service feature;
+
+    beforeModel() {
+        super.beforeModel(...arguments);
+
+        if (!this.session.user.isAdmin) {
+            return this.transitionTo('site');
+        }
+
+        if (!this.feature.customThemeSettings) {
+            return this.transitionTo('settings');
+        }
+    }
+
+    buildRouteInfoMetadata() {
+        return {
+            mainClasses: ['gh-main-wide']
+        };
+    }
+}

ghost/admin/app/templates/settings.hbs

@@ -15,20 +15,30 @@
                     <p>Basic publication details and site metadata</p>
                 </div>
             </LinkTo>
-            <button type="button" class="gh-setting-group" {{action (toggle "showBrandingModal" this)}} data-test-nav="branding">
-                <span class="blue">{{svg-jar "paint-palette"}}</span>
-                <div>
-                    <h4>Branding</h4>
-                    <p>Upload site logo and set accent color</p>
-                </div>
-            </button>
-            <LinkTo class="gh-setting-group" @route="settings.theme" data-test-nav="theme">
-                <span class="green">{{svg-jar "view-site"}}</span>
-                <div>
-                    <h4>Theme</h4>
-                    <p>Install and update themes</p>
-                </div>
-            </LinkTo>
+            {{#if (feature "customThemeSettings")}}
+                <LinkTo class="gh-setting-group" @route="settings.design" data-test-nav="design">
+                    <span class="blue">{{svg-jar "paint-palette"}}</span>
+                    <div>
+                        <h4>Design</h4>
+                        <p>Make things pretty (CHANGEME)</p>
+                    </div>
+                </LinkTo>
+            {{else}}
+                <button type="button" class="gh-setting-group" {{action (toggle "showBrandingModal" this)}} data-test-nav="branding">
+                    <span class="blue">{{svg-jar "paint-palette"}}</span>
+                    <div>
+                        <h4>Branding</h4>
+                        <p>Upload site logo and set accent color</p>
+                    </div>
+                </button>
+                <LinkTo class="gh-setting-group" @route="settings.theme" data-test-nav="theme">
+                    <span class="green">{{svg-jar "view-site"}}</span>
+                    <div>
+                        <h4>Theme</h4>
+                        <p>Install and update themes</p>
+                    </div>
+                </LinkTo>
+            {{/if}}
             <LinkTo class="gh-setting-group" @route="settings.navigation" data-test-nav="navigation">
                 <span class="pink">{{svg-jar "compass-2"}}</span>
                 <div>

ghost/admin/app/templates/settings/design.hbs

@@ -0,0 +1,15 @@
+<section class="gh-canvas">
+    <GhCanvasHeader class="gh-canvas-header">
+        <h2 class="gh-canvas-title" data-test-screen-title>
+            <LinkTo @route="settings">Settings</LinkTo>
+            <span>{{svg-jar "arrow-right"}}</span>
+            Design
+        </h2>
+    </GhCanvasHeader>
+
+    <section class="view-container">
+
+    </section>
+</section>
+
+{{outlet}}