core[patch]: fix API reference for draw_ascii (#29370)

typo: no `draw` but `draw_ascii` and other things

now, it works:
<img width="688" alt="image"
src="https://github.com/user-attachments/assets/5b5a8cc2-cf81-4a5c-b443-da0e4426556c"
/>

---------

Co-authored-by: Chester Curme <chester.curme@gmail.com>

libs/core/langchain_core/runnables/graph_ascii.py

@@ -221,24 +221,37 @@ def draw_ascii(vertices: Mapping[str, str], edges: Sequence[LangEdge]) -> str:
         str: ASCII representation
 
     Example:
-        >>> vertices = [1, 2, 3, 4]
+
-        >>> edges = [(1, 2), (2, 3), (2, 4), (1, 4)]
+        .. code-block:: python
-        >>> print(draw(vertices, edges))
+
-        +---+     +---+
+            from langchain_core.runnables.graph_ascii import draw_ascii
-        | 3 |     | 4 |
+
-        +---+    *+---+
+            vertices = {1: "1", 2: "2", 3: "3", 4: "4"}
-          *    **   *
+            edges = [
-          *  **     *
+                (source, target, None, None)
-          * *       *
+                for source, target in [(1, 2), (2, 3), (2, 4), (1, 4)]
-        +---+       *
+            ]
-        | 2 |      *
+
-        +---+     *
+
-             *    *
+            print(draw_ascii(vertices, edges))
-              *  *
+
-               **
+        .. code-block:: none
+
                  +---+
                  | 1 |
                  +---+
+                 *    *
+                *     *
+               *       *
+            +---+       *
+            | 2 |       *
+            +---+**     *
+              *    **   *
+              *      ** *
+              *        **
+            +---+     +---+
+            | 3 |     | 4 |
+            +---+     +---+
     """
     # NOTE: coordinates might me negative, so we need to shift
     # everything to the positive plane before we actually draw it.