feat: add help and about pages with sidebar navigation buttons

src/app.component.simple.html

@@ -29,6 +29,7 @@
     (searchOptionsChange)="onHeaderSearchOptionsChange($event)"
     (markdownPlaygroundSelected)="setView('markdown-playground')"
     (parametersOpened)="setView('parameters')"
+    (helpPageRequested)="openHelpPage()"
   ></app-shell-nimbus-layout>
 } @else {
 <main class="relative flex min-h-screen flex-col bg-bg-main text-text-main lg:flex-row lg:h-screen lg:overflow-hidden">