Update explainer: intro, goals, system prompt (#201)

SHA: 8c88a60
Reason: push, by michaelwasserman

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: michaelwasserman

index.html

@@ -8,7 +8,7 @@
   <meta content="Bikeshed version 0ef803fdf, updated Tue Jan 6 11:59:39 2026 -0800" name="generator">
   <link href="https://webmachinelearning.github.io/prompt-api" rel="canonical">
   <link href="https://www.w3.org/2008/site/images/favicon.ico" rel="icon">
-  <meta content="63d589ed738e2e9de7bcf73d96dd2bd6b69cbd40" name="revision">
+  <meta content="8c88a6022af8014a3b9d8ce64fd375e5de8d713f" name="revision">
   <meta content="dark light" name="color-scheme">
   <link href="https://www.w3.org/StyleSheets/TR/2021/dark.css" media="(prefers-color-scheme: dark)" rel="stylesheet" type="text/css">
 <style>/* Boilerplate: style-autolinks */
@@ -743,7 +743,7 @@
 </p>
    <h1 class="no-ref p-name" id="title">Prompt API</h1>
    <p id="w3c-state"><a href="https://www.w3.org/standards/types/#CG-DRAFT">Draft Community Group Report</a>,
-    <time class="dt-updated" datetime="2026-04-02">2 April 2026</time></p>
+    <time class="dt-updated" datetime="2026-04-10">10 April 2026</time></p>
    <details open>
     <summary>More details about this document</summary>
     <div data-fill-with="spec-metadata">