Re-organize directory structure (#4971)

See discussion in #2491

Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>

stdlib/_json.pyi

@@ -0,0 +1,38 @@
+from typing import Any, Callable, Dict, Optional, Tuple
+
+class make_encoder:
+    sort_keys: Any
+    skipkeys: Any
+    key_separator: Any
+    indent: Any
+    markers: Any
+    default: Any
+    encoder: Any
+    item_separator: Any
+    def __init__(
+        self,
+        markers: Optional[Dict[int, Any]],
+        default: Callable[[Any], Any],
+        encoder: Callable[[str], str],
+        indent: Optional[int],
+        key_separator: str,
+        item_separator: str,
+        sort_keys: bool,
+        skipkeys: bool,
+        allow_nan: bool,
+    ) -> None: ...
+    def __call__(self, obj: object, _current_indent_level: int) -> Any: ...
+
+class make_scanner:
+    object_hook: Any
+    object_pairs_hook: Any
+    parse_int: Any
+    parse_constant: Any
+    parse_float: Any
+    strict: bool
+    # TODO: 'context' needs the attrs above (ducktype), but not __call__.
+    def __init__(self, context: make_scanner) -> None: ...
+    def __call__(self, string: str, index: int) -> Tuple[Any, int]: ...
+
+def encode_basestring_ascii(s: str) -> str: ...
+def scanstring(string: str, end: int, strict: bool = ...) -> Tuple[str, int]: ...