DeveloperGuide.md: Add ToC

docs/DeveloperGuide.md

@@ -3,8 +3,28 @@ layout: page
 title: Developer Guide
 ---
 
-- Table of Contents
-  {:toc}
+## Table of Contents
+- [Acknowledgements](#acknowledgements)
+- [Setting up, getting started](#setting-up-getting-started)
+- [Design](#design)
+  - [Architecture](#architecture)
+  - [UI component](#ui-component)
+  - [Logic component](#logic-component)
+  - [Model component](#model-component)
+  - [Storage component](#storage-component)
+  - [Common classes](#common-classes)
+- [Implementation](#implementation)
+  - [Add feature](#add-feature)
+  - [Save feature](#save-feature)
+  - [\[Proposed\] Undo/redo feature](#proposed-undo/redo-feature)
+- [Documentation, logging, testing, configuration, dev-ops](#documentation-logging-testing-configuration-dev-ops)
+- [Appendix: Requirements](#appendix-requirements)
+  - [Product scope](#product-scope)
+  - [User stories](#user-stories)
+  - [Use cases](#use-cases)
+  - [Non-Functional Requirements](#non-functional-requirements)
+  - [Glossary](#glossary)
+- [Appendix: Instructions for manual testing](#appendix-instructions-for-manual-testing)
 
 ---