docs: Improve Docs

[Gustl22]

Description

Improve the documentation for:

• Getting started:
  • Fix typos from docs: fix typo in getting_started.md #1678
  • Call stop in low latency, missing completion event (PlayerMode.lowLatency and setReleaseMode don't work together (Android) #1489)
  • Set prefix for AssetSource via AudioCache (Enabling to use Asset source without adding it a prefix #1620, Audio doesn't work in windows app after doing build #1639)
• Troubleshooting guide:
  • Verify audio format, e.g. with Aconvert
  • Change heading size of web-cors-policy
• Example:
  • README: How to setup example with melos, tab descriptions
  • example.md: Add Simple (one-page) Example for pub.dev, see https://dart.dev/tools/pub/package-layout#examples (How do you download the files here? #1616)
  • Showcase for using play in addPostFrameCallback

See #1650

Checklist

• The title of my PR starts with a Conventional Commit prefix (fix:, feat:, refactor:,
  docs:, chore:, test:, ci: etc).
• I have read the Contributor Guide and followed the process outlined for submitting PRs.
• I have updated/added tests for ALL new/updated/fixed functionality.
• I have updated/added relevant documentation and added dartdoc comments with ///, where necessary.
• I have updated/added relevant examples in example.

Breaking Change

• Yes, this is a breaking change.
• No, this is not a breaking change.

Related Issues

#1650

[Gustl22]

If need to split in multiple Merge Requests, let me know ;D

[spydon]

Very nice! 🍻

[Gustl22]

Thank you for reviewing. Also I'm not that fluent in english. So I don't mind if you have some bigger proposals.

[spydon]

Thank you for reviewing. Also I'm not that fluent in english. So I don't mind if you have some bigger proposals.

I think it looks good. :)