Don't use internal templates anymore.

Blag will throw an error if a template is not found locally. The error
message contains an explanation for the user on where to get the missing
templates.

Quickstart will generate templates for the user in the working
directory.

Updated tests appropriately.

blag/quickstart.py

@@ -6,6 +6,10 @@
 from __future__ import annotations
 import configparser
 import argparse
+import shutil
+import os
+
+import blag
 
 
 def get_input(question: str, default: str) -> str:
@@ -33,6 +37,22 @@ def get_input(question: str, default: str) -> str:
     return reply
 
 
+def copy_templates() -> None:
+    """Copy templates into current directory.
+
+    It will not overwrite existing files.
+
+    """
+    print("Copying templates...")
+    try:
+        shutil.copytree(
+            os.path.join(blag.__path__[0], 'templates'),
+            'templates',
+        )
+    except FileExistsError:
+        print("Templates already exist. Skipping.")
+
+
 def quickstart(args: argparse.Namespace | None) -> None:
     """Quickstart.
 
@@ -71,3 +91,5 @@ def quickstart(args: argparse.Namespace | None) -> None:
     }
     with open('config.ini', 'w') as fh:
         config.write(fh)
+
+    copy_templates()