docs(aio): remove toc from all marketing pages

aio/content/marketing/contribute.md

@@ -1,4 +1,4 @@
-# Contribute to Angular
+<h1 class="no-toc">Contribute to Angular</h1>
 
 Help us build the framework of the future!
 

aio/content/marketing/docs.md

@@ -1,4 +1,4 @@
-# What is Angular?
+<h1 class="no-toc">What is Angular?</h1>
 
 Angular is a platform that makes it easy to build applications with the web. Angular combines declarative templates, dependency injection, end to end tooling, and integrated best practices to solve development challenges. Angular empowers developers to build applications that live on the web, mobile, or the desktop
 

aio/content/marketing/presskit.html

@@ -1,4 +1,4 @@
-<h1>Press Kit</h1>
+<h1 class="no-toc">Press Kit</h1>
 <div class="presskit-container l-space-neg-top-8">
   <div class="presskit-row">
     <div class="presskit-inner">

aio/content/marketing/resources.html

@@ -1,2 +1,2 @@
-<h1>Explore Angular Resources</h1>
+<h1 class="no-toc">Explore Angular Resources</h1>
 <aio-resource-list></aio-resource-list>