Gh pages deploy fix (#5669)

* fix(app):redirect after 404

* fix(app):docs building script

* fix(app):add gulpfile for docs

* fix(app): directory splitting

* fix(app): build docs script

* fix(app): build docs script

* fix(app): build docs script

* fix(app): relative path for scss

* fix(app): relative path for scss

* fix(app): relative path for scss

* fix(app):fix footer icons

* fix(app):fix footer icons

* fix(app):fix footer icons

* fix(app):config

* fix(app):remove small-social

* fix(docs): footer icons style

* fix(docs): material page index file

* fix(docs): descriptions and keyword

* fix(docs): og description

* fix(docs): og description and title

* fix(docs): dem,o branch url

* fix(docs): dynamic title for docs page

* fix(docs): remove unused script

* fix(docs): static title

Co-authored-by: Evgeny Lupanov <e.lupanov@akveo.com>

docs/structure.ts

@@ -6,6 +6,7 @@ export const structure = [
       {
         type: 'page',
         name: 'What is ngx-admin?',
+        description: 'Ngx-admin is Angular 9+ Bootstrap 4+ admin dashboard template. Free and Open Source to bootstrap the development of your product or to learn Angular.',
         children: [
           {
             type: 'block',