Move [p]backup command to cli command - redbot-setup backup (#3235)

* refactor: replace backup command with cli command

* chore(changelog): add towncrier entries

redbot/setup.py

@@ -7,7 +7,7 @@ import sys
 import re
 from copy import deepcopy
 from pathlib import Path
-from typing import Dict, Any, Optional
+from typing import Dict, Any, Optional, Union
 
 import appdirs
 import click
@@ -213,13 +213,13 @@ async def do_migration(
     return new_storage_details
 
 
-async def create_backup(instance: str) -> None:
+async def create_backup(instance: str, destination_folder: Path = Path.home()) -> None:
     data_manager.load_basic_configuration(instance)
     backend_type = get_current_backend(instance)
     if backend_type != BackendType.JSON:
         await do_migration(backend_type, BackendType.JSON)
     print("Backing up the instance's data...")
-    backup_fpath = await red_create_backup()
+    backup_fpath = await red_create_backup(destination_folder)
     if backup_fpath is not None:
         print(f"A backup of {instance} has been made. It is at {backup_fpath}")
     else:
@@ -293,6 +293,7 @@ async def remove_instance_interaction():
 @click.option("--debug", type=bool)
 @click.pass_context
 def cli(ctx, debug):
+    """Create a new instance."""
     level = logging.DEBUG if debug else logging.INFO
     redbot.logging.init_logging(level=level, location=Path.cwd() / "red_setup_logs")
     if ctx.invoked_subcommand is None:
@@ -356,6 +357,7 @@ def delete(
     drop_db: Optional[bool],
     remove_datapath: Optional[bool],
 ):
+    """Removes an instance."""
     loop = asyncio.get_event_loop()
     loop.run_until_complete(
         remove_instance(
@@ -368,6 +370,7 @@ def delete(
 @click.argument("instance", type=click.Choice(instance_list))
 @click.argument("backend", type=click.Choice(["json", "postgres"]))
 def convert(instance, backend):
+    """Convert data backend of an instance."""
     current_backend = get_current_backend(instance)
     target = get_target_backend(backend)
     data_manager.load_basic_configuration(instance)
@@ -393,6 +396,21 @@ def convert(instance, backend):
         )
 
 
+@cli.command()
+@click.argument("instance", type=click.Choice(instance_list))
+@click.argument(
+    "destination_folder",
+    type=click.Path(
+        exists=False, dir_okay=True, file_okay=False, resolve_path=True, writable=True
+    ),
+    default=Path.home(),
+)
+def backup(instance: str, destination_folder: Union[str, Path]) -> None:
+    """Backup instance's data."""
+    loop = asyncio.get_event_loop()
+    loop.run_until_complete(create_backup(instance, Path(destination_folder)))
+
+
 if __name__ == "__main__":
     try:
         cli()  # pylint: disable=no-value-for-parameter  # click