[Docs] Missing documentation for `Dataset.from_dict`
I'd like to work on this documentation issue. Hi I'd like to work on this. I can see the docstring is already in the code. 
Could you confirm:
1. Is this still available?
2. Should I add this to the main_classes.md file, or is there a specific 
   documentation file I should update?
3. Are there any formatting guidelines I should follow?

I'm new to contributing but eager to learn!
Documentation link: https://huggingface.co/docs/datasets/en/package_reference/main_classes

Link to method (docstring present): https://github.com/huggingface/datasets/blob/6f2502c5a026caa89839713f6f7c8b958e5e83eb/src/datasets/arrow_dataset.py#L1029

The docstring is present for the function, but seems missing from the official documentation for the `Dataset` class on HuggingFace.

The method in question:
```python
    @classmethod
    def from_dict(
        cls,
        mapping: dict,
        features: Optional[Features] = None,
        info: Optional[DatasetInfo] = None,
        split: Optional[NamedSplit] = None,
    ) -> "Dataset":
        """
        Convert `dict` to a `pyarrow.Table` to create a [`Dataset`].

        Important: a dataset created with from_dict() lives in memory
        and therefore doesn't have an associated cache directory.
        This may change in the future, but in the meantime if you
        want to reduce memory usage you should write it back on disk
        and reload using e.g. save_to_disk / load_from_disk.

        Args:
            mapping (`Mapping`):
                Mapping of strings to Arrays or Python lists.
            features ([`Features`], *optional*):
                Dataset features.
            info (`DatasetInfo`, *optional*):
                Dataset information, like description, citation, etc.
            split (`NamedSplit`, *optional*):
                Name of the dataset split.

        Returns:
            [`Dataset`]
        """
```