[Docs] Fix incomplete docstring for resnet.py

[Laurent2916]

Docstrings of some Upsampling and Downsampling layers were incomplete or missing.
I didn't know exactly what format to use for the docstrings since it doesn't seem to be specified in CONTRIBUTING.md

Overall, the various docstrings in the project don't all seem to be very consistent (some are formatted like Google's convention, some others look like Numpy's convention). Would it be a good idea to enable pydocstyle in ruff to overcome some of these issues ?

Like so (in pyproject.toml):

 [tool.ruff]
 # Never enforce `E501` (line length violations).
-ignore = ["C901", "E501", "E741", "W605"]
-select = ["C", "E", "F", "I", "W"]
+ignore = ["C901", "E501", "E741", "W605", "D102", "D107"]
+select = ["C", "E", "F", "I", "W", "D"]
 line-length = 119
 
+[tool.ruff.pydocstyle]
+# Use Google-style docstrings.
+convention = "google"
+
 # Ignore import violations in all `__init__.py` files.
 [tool.ruff.per-file-ignores]
 "__init__.py" = ["E402", "F401", "F403", "F811"]

[HuggingFaceDocBuilderDev]

The documentation is not available anymore as the PR was closed or merged.

[patrickvonplaten]

Amazing! Thanks a lot for the improvements here!