Add documentation for vCon Server modules

- Introduced new documentation files: CLAUDE.md, EXTENDING.md, VECTOR_STORAGE.md, example_link.py, and example_storage.py.
- CLAUDE.md provides guidance on build and run commands, code style guidelines, and testing practices.
- EXTENDING.md outlines how to implement new Link and Storage modules for the vCon Server, including best practices and testing instructions.
- VECTOR_STORAGE.md details the implementation and configuration of vector storage modules for semantic search capabilities.
- example_link.py and example_storage.py serve as practical examples of link and storage module structures, demonstrating basic functionality and logging practices.

Author: howethomas

docs/CLAUDE.md

@@ -0,0 +1,22 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Build and Run Commands
+- Install dependencies: `poetry install`
+- Run server: `docker compose up -d`
+- Scale up server: `docker compose up --scale conserver=4 -d`
+- Run single test: `poetry run pytest path/to/test_file.py::test_function_name -v`
+- Run all tests: `poetry run pytest`
+- Format code: `poetry run black .`
+
+## Code Style Guidelines
+- Use black for formatting (line length 120, skip string normalization)
+- Type annotations are required for function parameters and return values
+- Error handling: Use try/except with specific exceptions, log errors with logger
+- Imports: Group stdlib, third-party, and local imports separated by blank lines
+- Use docstrings for classes, methods, and functions with Args/Returns/Raises
+- Tests: Use pytest fixtures, mocks for external services, descriptive test names
+- Logging: Use structured logging with appropriate levels (info, debug, error)
+- Follow PEP 8 naming conventions (snake_case for functions/variables)
+- Use retry patterns with tenacity for external services