Adds a banner to the home page to feature the tutorials catalog and YT channel (#823)

Author: Steve Orvell

packages/lit-dev-content/site/css/home/1-splash.css

@@ -1,3 +1,25 @@
+#new-banner {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: #325cff;
+  color: white;
+  height: var(--header-height);
+}
+
+#new-banner > p {
+  text-align: center;
+}
+
+#new-banner a {
+  color: white;
+  font-weight: 800;
+}
+
+#new-banner a:hover {
+  text-decoration: underline;
+}
+
 #intro {
   display: flex;
   align-items: center;

packages/lit-dev-content/site/home/1-splash.html

@@ -1,3 +1,6 @@
+<section id="new-banner">
+  <p>📣 Check out our brand new <a href="{{site.baseurl}}/tutorials">Tutorials Catalog</a> and <a href="{{site.baseurl}}/youtube">YouTube Channel!</a></p>
+</section>
 <section id="intro">
   <div id="splashLogo" role="heading" aria-level="1">
     <img src="{{site.baseurl}}/images/logo.svg" aria-label="Lit" width="425" height="200" />