Ignore F401 for __init__.py files

These files routinely import other modules without immediately using
them with the intention of making them available to the importing
module. Moreover, they are rarely even supposed to be used within the
same __init__.py file. Marking all of them 'noqa: F410' is redundant.

docs/Coding-Conventions.md

@@ -858,13 +858,21 @@ import cheese_shop.brie
 
 ### [O.1.8] ❌ **DO NOT** Import definitions that are not used 💻
 
-> 💻 This rule is enforced by error code F401
+> 💻 This rule is enforced by error code F401, except in `__init__.py` files
+
+ℹ️ `__init__.py` files routinely import other modules without using them and therefore are exempt from this rule.
 
 ```python
 # Bad
 import os  # Assuming os is never used
 ```
 
+```python
+# Good - assuming we are in a __init__.py file
+from .mysubmodule import spam, eggs # OK even if neither are used in this module
+```
+
+
 ### [O.1.9] ❌ **DO NOT** Change an imported object's case 💻
 
 > 💻 This rule is enforced by error codes N811, N812, N813, N814, N817

ni_python_styleguide/config.ini

@@ -112,8 +112,11 @@ ignore =
     # I101 - The names in your from import are in the wrong order. (Enforced by E401)
     I101
 
-# We want to ignore missing docstrings in test methods as they are self documenting
-per-file-ignores= tests/**/test_*.py,tests/test_*.py:D100,D103,D102
+per-file-ignores=
+    # We want to ignore missing docstrings in test methods as they are self documenting
+    tests/**/test_*.py,tests/test_*.py:D100,D103,D102
+    # __init__.py files import other modules routinely with directly using them
+    __init__.py:F401
 
 # Flake8 includes mccabe by default.
 # We have yet to evaluate it, so ignore the errors for now