refactor: 🚚 rename to extensions.py from custom_checks.py

src/check_datapackage/__init__.py

@@ -2,9 +2,9 @@
 
 from .check import check
 from .config import Config
-from .custom_check import CustomCheck
 from .examples import example_package_properties, example_resource_properties
 from .exclusion import Exclusion
+from .extensions import CustomCheck
 from .issue import Issue
 from .read_json import read_json
 

src/check_datapackage/check.py

@@ -7,8 +7,8 @@
 
 from check_datapackage.config import Config
 from check_datapackage.constants import DATA_PACKAGE_SCHEMA_PATH, GROUP_ERRORS
-from check_datapackage.custom_check import apply_custom_checks
 from check_datapackage.exclusion import exclude
+from check_datapackage.extensions import apply_custom_checks
 from check_datapackage.internals import (
     _filter,
     _flat_map,

src/check_datapackage/config.py

@@ -1,8 +1,8 @@
 from dataclasses import dataclass, field
 from typing import Literal
 
-from check_datapackage.custom_check import CustomCheck
 from check_datapackage.exclusion import Exclusion
+from check_datapackage.extensions import CustomCheck
 
 
 @dataclass

tests/test_custom_check.py

@@ -1,10 +1,10 @@
 from check_datapackage.check import check
 from check_datapackage.config import Config
-from check_datapackage.custom_check import CustomCheck
 from check_datapackage.examples import (
     example_package_properties,
     example_resource_properties,
 )
+from check_datapackage.extensions import CustomCheck
 from check_datapackage.issue import Issue
 
 lowercase_check = CustomCheck(