move paragraph into background

per w3c/strategy#447 (comment)

2024/immersive-web-wg.html

@@ -160,6 +160,14 @@ <h1 id="title">[PROPOSED] Immersive Web Working Group Charter</h1>
     </section>
 
     <section id="background" class="background">
+        <h2>Motivation and Background</h2>
+        <p>
+          A new generation of head-mounted displays and environment sensing capabilities on mobile devices are enabling
+          augmented
+          and virtual reality (collectively known as XR) to emerge as a critical field of evolution for human-machine
+          interactions. Due to its inherent low friction and support for ephemeral experiences, the Web provides a
+          promising
+          ecosystem for the creation, distribution, and experiencing of XR content, applications, and services. </p>
     </section>
 
     <section id="scope" class="scope">
@@ -176,13 +184,6 @@ <h2>Scope</h2>
           that are embeddable in the Web of today, enabling progressive enhancement
           of existing sites.
         </p>
-        <p>
-          A new generation of head-mounted displays and environment sensing capabilities on mobile devices are enabling
-          augmented
-          and virtual reality (collectively known as XR) to emerge as a critical field of evolution for human-machine
-          interactions. Due to its inherent low friction and support for ephemeral experiences, the Web provides a
-          promising
-          ecosystem for the creation, distribution, and experiencing of XR content, applications, and services. </p>
         <p>
           The <strong>scope</strong> of the Immersive Web Working Group charter is to
           define APIs which: