feat: add CLI for database creation, update .gitignore, and remove ol…

…d JSON configs

- Introduced a new `cli.py` script using `Click` for creating Notion databases.
- Updated `.gitignore` to include the `plugins` directory.
- Removed outdated JSON configuration files for client engagement, fashion recommender, and training tasks.
- Added new tests for the Notion client, configuration, and model modules.
- Refactored Notion API client and configuration loading for better modularity.

.gitignore

@@ -11,3 +11,5 @@ venv/
 # VSCode settings
 .vscode/
 
+plugins
+

cli.py

@@ -0,0 +1,17 @@
+import click
+from notion_client.api import NotionClient
+from notion_client.config import ConfigManager
+
+@click.group()
+def cli():
+    pass
+
+@cli.command()
+@click.option('--schema', required=True, help='Schema name without extension.')
+@click.option('--tasks', required=True, help='Tasks name without extension.')
+def create_database(schema, tasks):
+    # Implementation as above
+    pass
+
+if __name__ == "__main__":
+    cli()