replace deprecated appdirs with platformdirs fork

docs/configuration.md

@@ -32,7 +32,7 @@ Use `cli.save_config()` to save the user's configuration file. It will be writte
 
 # Configuration File Location
 
-MILC uses [appdirs](https://github.com/ActiveState/appdirs) to determine the configuration file location. You can set your application's name and author by using `milc.set_metadata`:
+MILC uses [platformdirs](https://github.com/tox-dev/platformdirs) to determine the configuration file location. You can set your application's name and author by using `milc.set_metadata`:
 
 ```python
 from milc import set_metadata

milc/milc.py

@@ -21,8 +21,8 @@
 
 import argcomplete
 import colorama
-from appdirs import user_config_dir
 from halo import Halo  # type: ignore
+from platformdirs import user_config_dir
 from spinners.spinners import Spinners  # type: ignore
 
 from .ansi import MILCFormatter, ansi_colors, ansi_config, ansi_escape, format_ansi

requirements-dev.txt

@@ -7,6 +7,5 @@ mkdocs-material<9
 mypy
 nose2
 pygments
-types-appdirs
 semver
 yapf

setup.py

@@ -46,10 +46,10 @@
         ],
         python_requires='>=3.7',
         install_requires=[
-            "appdirs",
             "argcomplete",
             "colorama",
             "halo",
+            "platformdirs",
             "spinners",
             "types-colorama",
         ],