feat(demo): add landing page with docs (#1951)

docs/app/@theme/services/styles.service.ts

@@ -0,0 +1,33 @@
+/**
+ * @license
+ * Copyright Akveo. All Rights Reserved.
+ * Licensed under the MIT License. See License.txt in the project root for license information.
+ */
+
+import { Inject, Injectable } from '@angular/core';
+import { DOCS } from '../../app.options';
+
+@Injectable()
+export class NgxStylesService {
+
+  constructor(@Inject(DOCS) private docs) {
+  }
+
+  mapThemedValues(classStyles: any): any {
+    return classStyles.map(item => {
+      item.styles.map(prop => {
+        prop.themedValues = [];
+        for (const themeName in this.docs.themes) {
+          if (this.docs.themes.hasOwnProperty(themeName)) {
+            prop.themedValues.push({
+              theme: this.docs.themes[themeName].name,
+              value: this.docs.themes[themeName].data[prop.name].value,
+            });
+          }
+        }
+        return prop;
+      });
+      return item;
+    });
+  }
+}