Fix typo in Ray Tune PyTorch Lightning docs (#52756)

<!-- Thank you for your contribution! Please review
https://github.com/ray-project/ray/blob/master/CONTRIBUTING.rst before
opening a pull request. -->

<!-- Please add a reviewer to the assignee section when you create a PR.
If you don't have the access to it, we will shortly find a reviewer and
assign them to your PR. -->

## Why are these changes needed?

<!-- Please give a short summary of the change and the problem this
solves. -->
Fixes small typo in docs.

## Related issue number

<!-- For example: "Closes #1234" -->

## Checks

- [x] I've signed off every commit(by using the -s flag, i.e., `git
commit -s`) in this PR.
- [ ] I've run `scripts/format.sh` to lint the changes in this PR.
- [ ] I've included any doc changes needed for
https://docs.ray.io/en/master/.
- [ ] I've added any new APIs to the API Reference. For example, if I
added a
method in Tune, I've added it in `doc/source/tune/api/` under the
           corresponding `.rst` file.
- [ ] I've made sure the tests are passing. Note that there might be a
few flaky tests, see the recent failures at https://flakey-tests.ray.io/
- Testing Strategy
   - [ ] Unit tests
   - [ ] Release tests
   - [x] This PR is not tested :(

Signed-off-by: Ishaan Mehta <45380942+ishaan-mehta@users.noreply.github.com>

Author: ishaan-mehta

doc/source/tune/examples/tune-pytorch-lightning.ipynb

@@ -302,7 +302,7 @@
     "# The maximum training epochs\n",
     "num_epochs = 5\n",
     "\n",
-    "# Number of sampls from parameter space\n",
+    "# Number of samples from parameter space\n",
     "num_samples = 10"
    ]
   },