Source links broken
This is done in #3943 to go along with [doc-builder#146](https://github.com/huggingface/doc-builder/pull/146).

Note that this will only work for future versions, so once those two are merged, the actual v2.0.0 doc should be fixed. The easiest is to cherry-pick this commit on the v2.0.0 release branch (or on a new branch created from the 2.0.0 tag, with a name that triggers the doc building job, for instance v2.0.0-release)
## Describe the bug

The source links of v2.0.0 docs are broken:

For exmaple, clicking the source button of this [class](https://huggingface.co/docs/datasets/v2.0.0/en/package_reference/main_classes#datasets.ClassLabel) will direct users to `https://github.com/huggingface/datasets/blob/v2.0.0/src/datasets/features/features.py#L747`

here, the `v2.0.0` should be `2.0.0`.


## Steps to reproduce the bug
```python
# Sample code to reproduce the bug
```

## Expected results

Redirecting to this link: `https://github.com/huggingface/datasets/blob/2.0.0/src/datasets/features/features.py#L747`

## Actual results
Described above.

## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version:
- Platform:
- Python version:
- PyArrow version:

Source links broken 
 ## Describe the bug

The source links of v2.0.0 docs are broken:

For exmaple, clicking the source button of this [class](https://huggingface.co/docs/datasets/v2.0.0/en/package_reference/main_classes#datasets.ClassLabel) will direct users to `https://github.com/huggingface/datasets/blob/v2.0.0/src/datasets/features/features.py#L747`

here, the `v2.0.0` should be `2.0.0`.


## Steps to reproduce the bug
```python
# Sample code to reproduce the bug
```

## Expected results

Redirecting to this link: `https://github.com/huggingface/datasets/blob/2.0.0/src/datasets/features/features.py#L747`

## Actual results
Described above.

## Environment info
<!-- You can run the command `datasets-cli env` and copy-and-paste its output below. -->
- `datasets` version:
- Platform:
- Python version:
- PyArrow version:
 
 This is done in #3943 to go along with [doc-builder#146](https://github.com/huggingface/doc-builder/pull/146).

Note that this will only work for future versions, so once those two are merged, the actual v2.0.0 doc should be fixed. The easiest is to cherry-pick this commit on the v2.0.0 release branch (or on a new branch created from the 2.0.0 tag, with a name that triggers the doc building job, for instance v2.0.0-release)