Re-organize directory structure (#4971)

See discussion in #2491

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

stdlib/curses/textpad.pyi

@@ -0,0 +1,11 @@
+from _curses import _CursesWindow
+from typing import Callable, Optional, Union
+
+def rectangle(win: _CursesWindow, uly: int, ulx: int, lry: int, lrx: int) -> None: ...
+
+class Textbox:
+    stripspaces: bool
+    def __init__(self, win: _CursesWindow, insert_mode: bool = ...) -> None: ...
+    def edit(self, validate: Optional[Callable[[int], int]] = ...) -> str: ...
+    def do_command(self, ch: Union[str, int]) -> None: ...
+    def gather(self) -> str: ...