fix: Change memory server default filename from memory.json to memory.jsonl

The Memory MCP server uses JSONL format (JSON Lines) where each line
contains a separate JSON object, but was using a .json file extension.
This caused IDE lint errors and confusion since the file is not valid JSON.

Changes:
- Update default filename in index.ts from memory.json to memory.jsonl
- Update documentation references in README.md
- Maintain backward compatibility for existing MEMORY_FILE_PATH configs

Fixes #2361

Co-authored-by: Ola Hungerford <olaservo@users.noreply.github.com>

src/memory/index.ts

@@ -11,7 +11,7 @@ import path from 'path';
 import { fileURLToPath } from 'url';
 
 // Define memory file path using environment variable with fallback
-const defaultMemoryPath = path.join(path.dirname(fileURLToPath(import.meta.url)), 'memory.json');
+const defaultMemoryPath = path.join(path.dirname(fileURLToPath(import.meta.url)), 'memory.jsonl');
 
 // If MEMORY_FILE_PATH is just a filename, put it in the same directory as the script
 const MEMORY_FILE_PATH = process.env.MEMORY_FILE_PATH