docs: Update Capabilities/index.md to include Agentic Development

- Auto-generated by Update-DocumentationIndex.ps1
- Added Agentic Development entry to capabilities table

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: MariusStorhaug

src/docs/Capabilities/index.md

@@ -22,6 +22,7 @@ and design relate and evolve.
 | [Downstream Release Propagation](downstream-release-propagation/index.md) | How a release in one repository propagates to the repositories that depend on it, via a delegated agent pull request. |
 | [VS Code Extension Framework](vscode-extension-framework/index.md) | How a VS Code extension is built, tested, versioned, packaged, and published — one GitHub-native pipeline, opt-in from a template and a single settings file. |
 | [PowerShell on GitHub](powershell-on-github/index.md) | How we make GitHub a first-class platform for PowerShell through reusable modules, actions, and capability gaps we close over time. |
+| [Agentic Development](agentic-development/index.md) | The framework for org-scoped docs and memory repositories that give agents project-specific standards, working knowledge, and behavior. |
 
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