[docs] Add thunderfx to dynamo/index.rst (#2421)

Author: crcrpar

docs/source/reference/dynamo/index.rst

@@ -7,3 +7,4 @@ thunder.dynamo
     :toctree:
 
     ThunderCompiler
+    thunderfx

thunder/dynamo/compiler.py

@@ -207,7 +207,8 @@ def save_reproducer_to_folder(
 
 
 def thunderfx(fn: Callable, /, **kwargs) -> Callable:
-    """Compiles a callable (function or model) by using Thunder as the backend of :func:`torch.compile`
+    """Compiles a callable (function or model) by using Thunder as the backend of :func:`torch.compile`.
+
     Args:
         fn: A :class:`~torch.nn.Module` or a function to compile.
     Keyword Args: