fix: Update Total cost description in intro to be sum, not average

The previous sed command didn't work due to a unicode apostrophe character.

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

content.py

@@ -29,7 +29,7 @@ INTRO_PARAGRAPH = """
         <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> A macro-average of the agent’s cost per problem across all categories, in USD. Each category contributes equally.
+        <strong>Total cost:</strong> The sum of the agent's cost across all categories, in USD.
     </li>
 </ul>