Reorganize documentation navigation into Core Concepts vs Advanced Topics

Move essential concepts to Core Concepts section:
- Memory Types, Memory Editing, Memory Lifecycle, Vector Store Backends
- Authentication and Configuration (operational essentials)

Move specialized features to Advanced Topics section:
- Query Optimization, Recency Boost, Advanced Vector Store Config
- Contextual Grounding

This provides clearer learning path for users: start with core concepts,
then explore advanced optimization techniques.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: abrookins

mkdocs.yml

@@ -81,17 +81,17 @@ nav:
 
   - Core Concepts:
     - Memory Types: memory-types.md
+    - Memory Editing: memory-editing.md
+    - Memory Lifecycle: memory-lifecycle.md
+    - Vector Store Backends: vector-store-backends.md
     - Authentication: authentication.md
     - Configuration: configuration.md
 
-  - Advanced Features:
+  - Advanced Topics:
     - Query Optimization: query-optimization.md
-    - Contextual Grounding: contextual-grounding.md
-    - Memory Editing: memory-editing.md
-    - Memory Lifecycle: memory-lifecycle.md
     - Recency Boost: recency-boost.md
-    - Vector Store Backends: vector-store-backends.md
     - Advanced Vector Store Config: vector-store-advanced.md
+    - Contextual Grounding: contextual-grounding.md
 
   - API Interfaces:
     - REST API: api.md