Frontent dev env (#247)

* Added frontend development files/environment

* More items-categories related removals

* Improvements in pages templates (inc. static pages)

* Improvements in video player

* Added empty home page message + cta

* Updates in media, playlist and management pages

* Improvements in material icons font loading

* Replaced media & playlists links in frontend dev-env

* frontend package version update

* chnaged frontend dev url port

* static files update

* Changed default position of theme switcher

* enabled frontend docker container

frontend/config/templates/static/aboutPage.html

@@ -0,0 +1,18 @@
+<div id="app-header"></div>
+<div id="app-sidebar"></div>
+<div class="page-main-wrap">
+  <div class="page-main">
+    <div class="page-main-inner">
+      <div class="custom-page-wrapper">
+        <h2>About</h2>
+        <hr />
+        <p>
+          <a href="https://mediacms.io">MediaCMS</a> is a modern, fully featured open source video and media CMS. It is
+          developed to meet the needs of modern web platforms for viewing and sharing media.
+        </p>
+      </div>
+    </div>
+    <div class="page-sidebar-content-overlay"></div>
+  </div>
+</div>
+<div id="app-footer"></div>