Update trainer.fit docstring (#17981)

(cherry picked from commit 4532ef7)

Author: carmocca

src/lightning/pytorch/trainer/trainer.py

@@ -510,14 +510,12 @@ def fit(
 
             val_dataloaders: An iterable or collection of iterables specifying validation samples.
 
-            ckpt_path: Path/URL of the checkpoint from which training is resumed. Could also be one of two special
-                keywords ``"last"`` and ``"hpc"``. If there is no checkpoint file at the path, an exception is raised.
-                If resuming from mid-epoch checkpoint, training will start from the beginning of the next epoch.
-
-            datamodule: An instance of :class:`~lightning.pytorch.core.datamodule.LightningDataModule`.
             datamodule: A :class:`~lightning.pytorch.core.datamodule.LightningDataModule` that defines
                 the :class:`~lightning.pytorch.core.hooks.DataHooks.train_dataloader` hook.
 
+            ckpt_path: Path/URL of the checkpoint from which training is resumed. Could also be one of two special
+                keywords ``"last"`` and ``"hpc"``. If there is no checkpoint file at the path, an exception is raised.
+
         Raises:
             TypeError:
                 If ``model`` is not :class:`~lightning.pytorch.core.module.LightningModule` for torch version less than