Update intro text to focus on motivation rather than metrics

Simplified the above-the-fold description to emphasize:
- Why the index exists (need for standardized agent evaluation)
- What it provides (aggregated performance + cost view)
- Who benefits (developers and researchers)

Moved detailed metric explanations to the About page.

Co-authored-by: openhands <openhands@all-hands.dev>

content.py

@@ -21,20 +21,15 @@ INTRO_PARAGRAPH = """
 </p>
 
 <p>
-    <strong>OpenHands Index</strong> provides an aggregated view of agent performance and efficiency across all benchmarks in all categories. We report:
+    <strong>OpenHands Index</strong> is a comprehensive benchmark for evaluating AI coding agents across real-world software engineering tasks. As agents become more capable, we need standardized ways to measure their performance across diverse challenges—from fixing bugs to building applications.
 </p>
 
-<ul class="info-list">
-    <li>
-        <strong>Average score:</strong> A macro-average of the five category-level average scores. Each category contributes equally, regardless of how many benchmarks it includes. This ensures fair comparisons across agents with different domain strengths.
-    </li>
-    <li>
-        <strong>Total cost:</strong> The sum of the agent's cost across all categories, in USD.
-    </li>
-</ul>
+<p>
+    Our index aggregates results from multiple benchmarks spanning five categories, providing a single view of both <strong>performance</strong> and <strong>cost efficiency</strong>. This enables fair comparisons between agents, helping developers and researchers choose the right tool for their needs.
+</p>
 
 <p>
-    This view is designed for quick comparison of general-purpose coding agents. For more details on how we calculate scores and cost, please see the <a href="/about" style="color: #6366F1; text-decoration: underline;">About</a> Page.
+    For methodology details, see the <a href="/about" style="color: #6366F1; text-decoration: underline;">About</a> page.
 </p>
 """
 SCATTER_DISCLAIMER = """