[DOCS] Add PR reference and parallel processing note

- Add CPU cores (16) to benchmark methodology
- Add note about pcntl_fork and --parallel-workers
- Add References section with link to PR TYPO3-Documentation#1143

Author: CybotTM

docs/index.html

@@ -967,8 +967,19 @@ <h2>Benchmark Methodology</h2>
                     <td>Large Docs</td>
                     <td>TYPO3CMS-Reference-CoreApi (957 files)</td>
                 </tr>
+                <tr>
+                    <td>CPU Cores</td>
+                    <td>16 (auto-detected, no container limits)</td>
+                </tr>
             </table>
 
+            <p style="color: var(--text-muted); margin-top: 1rem; font-size: 0.9rem;">
+                <strong>Parallel Processing:</strong> The feature branch uses <code>pcntl_fork</code>
+                for parallel rendering, automatically detecting available CPU cores. Your results
+                may vary depending on available cores. Use <code>--parallel-workers=N</code> to
+                manually set the worker count.
+            </p>
+
             <h3 style="margin-top: 2rem;">Reproduce These Benchmarks</h3>
             <p style="color: var(--text-muted); margin-bottom: 1rem;">
                 Follow these steps to reproduce the benchmark results on your own machine:
@@ -1029,6 +1040,15 @@ <h4 style="margin-bottom: 0.5rem;">Prerequisites</h4>
                 with naming convention: <code>{branch}_{scenario}_{docs}_{timestamp}.json</code>
             </p>
         </div>
+
+        <!-- References -->
+        <div class="card">
+            <h2>References</h2>
+            <ul style="margin: 0; padding-left: 1.5rem;">
+                <li><a href="https://github.com/TYPO3-Documentation/render-guides/pull/1143">PR #1143</a> &mdash; Original performance optimization proposal and discussion</li>
+                <li><a href="https://github.com/CybotTM/render-guides/tree/feature/php-8.5-only">Feature Branch</a> &mdash; Source code for this implementation</li>
+            </ul>
+        </div>
     </main>
 
     <footer>