Re-organize directory structure (#4971)

See discussion in #2491

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

stdlib/tkinter/simpledialog.pyi

@@ -0,0 +1,27 @@
+from tkinter import Event, Misc, Toplevel
+from typing import Any, List, Optional
+
+class Dialog(Toplevel):
+    def __init__(self, parent: Optional[Misc], title: Optional[str] = ...) -> None: ...
+    def body(self, master) -> None: ...
+    def buttonbox(self): ...
+
+class SimpleDialog:
+    def __init__(
+        self,
+        master: Optional[Misc],
+        text: str = ...,
+        buttons: List[str] = ...,
+        default: Optional[int] = ...,
+        cancel: Optional[int] = ...,
+        title: Optional[str] = ...,
+        class_: Optional[str] = ...,
+    ) -> None: ...
+    def go(self) -> Optional[int]: ...
+    def return_event(self, event: Event[Misc]) -> None: ...
+    def wm_delete_window(self) -> None: ...
+    def done(self, num: int) -> None: ...
+
+def askfloat(title: Optional[str], prompt: str, **kwargs: Any) -> float: ...
+def askinteger(title: Optional[str], prompt: str, **kwargs: Any) -> int: ...
+def askstring(title: Optional[str], prompt: str, **kwargs: Any) -> str: ...