docs/audio_tone: Add documentation about the audio tone driver

[linguini1]

Summary

This commit adds some documentation about the audio tone driver, how to use it and links to it from the main audio component page. I also added some back links to other audio docs there for convenience.

Impact

Docs only.

Testing

Local build.

[github-actions]

MemBrowse Memory Report

hifive1-revb

• flash: .text -4 B (-0.0%, 83,248 B / 4,194,304 B, total: 2% used)
  No memory changes detected for:
• arduino-mega2560
• esp32-devkitc
• mirtoo
• qemu-armv8a
• qemu-intel64
• rx65n-rsk2mb
• s698pm-dkit
• stm32-nucleo-f103rb

[linguini1]

Just like the other CI items, we can maybe update the runs so that membrowse doesn't run on docs only PRs. What do you think @simbit18 ?

[simbit18]

@linguini1 I agree, too.
Hi @michael-membrowse, could you exclude the membrowse run where the PR contains only documentation?

Add these other cases as well, so we can save some time.

pull_request:
    paths-ignore:
      - "AUTHORS"
      - "CONTRIBUTING.md"
      - "**/CODEOWNERS"
      - "Documentation/**"
  push:
    paths-ignore:
      - "AUTHORS"
      - "CONTRIBUTING.md"
      - "Documentation/**"

[michael-membrowse]

Hi @simbit18,
When a PR doesn't contain real code change,
MemBrowse runs in "identical" mode.
Meaning there is no build and no report generation. Only upload of metadata so the commit chain in the MemBrowse portal will be intact. Its very minimal in terms of CI minutes.

[simbit18]

Hi @michael-membrowse , here you can see the time taken by MemBrowse to run this documentation-only PR (38m 10s )
https://github.com/apache/nuttx/actions/runs/29209845109/usage

[linguini1]

The most minimal number of minutes is none at all!