chore: adjust docstrings in the audio package

[masci]

Related Issues

• fixes Docstrings - haystack.components.audio #7098

Proposed Changes:

Adjust the docstrings to the Haystack convention. Also improved a bit the content.

How did you test it?

Notes for the reviewer

Checklist

• I have read the contributors guidelines and the code of conduct
• I have updated the related issue with new insights and changes
• I added unit tests and updated the docstrings
• I've used one of the conventional commit types for my PR title: fix:, feat:, build:, chore:, ci:, docs:, style:, refactor:, perf:, test:.
• I documented my code
• I ran pre-commit hooks and fixed any issue

[anakin87]

Good to merge after some minor changes.

[coveralls]

Pull Request Test Coverage Report for Build 8083846830

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 41 unchanged lines in 5 files lost coverage.
• Overall coverage remained the same at 90.091%

---

Files with Coverage Reduction	New Missed Lines	%
components/websearch/searchapi.py	2	96.36%
dataclasses/document.py	3	93.81%
components/audio/whisper_local.py	6	91.3%
components/audio/whisper_remote.py	13	69.77%
components/websearch/serper_dev.py	17	69.84%

Totals
Change from base Build 8081267643:	0.0%
Covered Lines:	5264
Relevant Lines:	5843

---

💛 - Coveralls