refactor: Move submodules into an internal folder

Author: pawamoy

src/mkdocstrings_handlers/shell/config.py

@@ -0,0 +1,17 @@
+"""Deprecated. Import from `mkdocstrings_handlers.shell` directly."""
+
+# YORE: Bump 2: Remove file.
+
+import warnings
+from typing import Any
+
+from mkdocstrings_handlers.shell._internal import config
+
+
+def __getattr__(name: str) -> Any:
+    warnings.warn(
+        "Importing from `mkdocstrings_handlers.shell.config` is deprecated. Import from `mkdocstrings_handlers.shell` directly.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+    return getattr(config, name)

src/mkdocstrings_handlers/shell/handler.py

@@ -0,0 +1,17 @@
+"""Deprecated. Import from `mkdocstrings_handlers.shell` directly."""
+
+# YORE: Bump 2: Remove file.
+
+import warnings
+from typing import Any
+
+from mkdocstrings_handlers.shell._internal import handler
+
+
+def __getattr__(name: str) -> Any:
+    warnings.warn(
+        "Importing from `mkdocstrings_handlers.shell.handler` is deprecated. Import from `mkdocstrings_handlers.shell` directly.",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+    return getattr(handler, name)