docs: drop the live embed from the introduction

Removed on request. The demo let a reader change a headline and an accent on a
ten-second composition, which undersold the thing the page is arguing for — the
Showcase wall above it does more for that in less space.

The component and its build apparatus go with it in #2977; nothing else on the
page referenced them.

Author: ukimsanov

docs/introduction.mdx

@@ -5,7 +5,6 @@ description: "See what an AI agent can make with ordinary web technology."
 ---
 
 import { DocsVideo, ShowcaseWall } from "/snippets/docs-video.jsx";
-import { LiveReferenceProject } from "/snippets/live-reference-project.jsx";
 
 <div className="hf-docs-video-frame">
   <DocsVideo
@@ -33,16 +32,6 @@ Every tile below is a finished HyperFrames film. Open one to watch it with sound
 depending on live playback, so a slow machine does not drop moments from the
 finished video.
 
-## Change the project yourself
-
-This is the same real HTML project used in the first-video walkthrough. Change
-its words or accent, then press Play.
-
-<LiveReferenceProject
-  src="https://static.heygen.ai/hyperframes-oss/docs/reference-project/live/index-v2.html"
-  poster="https://static.heygen.ai/hyperframes-oss/docs/reference-project/live/poster-v2.jpg"
-/>
-
 ## Make one
 
 <Card title="Make your first video" icon="play" href="/quickstart" horizontal arrow>