Add a new option to use hash for release-note script (#8096)

This commit adds a new command-line argument for
`docs/script/release-note.sh`, which is `--previous-release-hash`.
It will allow us to generate the release note at more finer granularity.

The current help message is following,
```
Usage: ./docs/scripts/release-note.sh [--since DATE | --previous-release-hash HASH]
  --since DATE                    Generate notes since the given date (e.g., 2025-08-06)
  --previous-release-hash HASH    Generate notes since the given commit hash

Legacy usage (deprecated): ./docs/scripts/release-note.sh DATE
```

Fixes
- https://github.com/shader-slang/slang/issues/5188
- https://github.com/shader-slang/slang/issues/6887

---------

Co-authored-by: slangbot <ellieh+slangbot@nvidia.com>
Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>
Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

0 files changed, 0 insertions, 0 deletions