Remove init_config.py

It may become a bit unwieldy to make sure this matches the structure of default_config, given the amount of code repetition involved. It seems easier for a user to just create their own custom_config.yml file directly.

docs/source/getting_started/structure.rst

@@ -103,7 +103,6 @@ Below is the directory structure of manim:
         ├── family_ops.py         # Process family members
         ├── file_ops.py           # Process files and directories
         ├── images.py             # Read image
-        ├── init_config.py        # Configuration guide
         ├── iterables.py          # Functions related to list/dictionary processing
         ├── paths.py              # Curve path
         ├── rate_functions.py     # Some defined rate_functions

manimlib/__main__.py

@@ -4,7 +4,6 @@
 from manimlib import __version__
 from manimlib.config import manim_config
 from manimlib.config import parse_cli
-import manimlib.utils.init_config
 import manimlib.extract_scene
 from manimlib.window import Window
 
@@ -55,9 +54,6 @@ def main():
     args = parse_cli()
     if args.version and args.file is None:
         return
-    if args.config:
-        manimlib.utils.init_config.init_customization()
-        return
 
     run_scenes()
 

manimlib/config.py

@@ -147,11 +147,6 @@ def parse_cli():
             action="store_true",
             help="Show the output file in finder",
         )
-        parser.add_argument(
-            "--config",
-            action="store_true",
-            help="Guide for automatic configuration",
-        )
         parser.add_argument(
             "--file_name",
             help="Name for the movie or image file",

manimlib/default_config.yml

@@ -1,3 +1,13 @@
+# This file determines the default configuration for how manim is
+# run, including names for directories it will write to, default
+# parameters for various classes, style choices, etc. To customize
+# your own, create a custom_config.yml file in whatever directory
+# you are running manim. For 3blue1brown, for instance, mind is
+# here: https://github.com/3b1b/videos/blob/master/custom_config.yml
+
+# Alternatively, you can create it whereever you like, and on running
+# manim, pass in `--config_file /path/to/custom/config/file.yml`
+
 directories:
   # Set this to true if you want the path to video files
   # to match the directory structure of the path to the