Fix missing volumes on audiobookshelf compose.yml

[michaelhodges]

Pull Request Title: Fix missing volumes on audiobookshelf compose.yml

Description

Add audiobooks, podcasts and metadata volumes mounted to local storage.
These three volumes are missing from the compose.yml file found on the offical docs.
https://www.audiobookshelf.org/docs/#docker-compose-install

• The purpose of the changes
  Volumes are missing and not mounted to local storage as outlined in templates.

Related Issues

• Issue #[issue number] (e.g., Fixes #[issue number])

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactoring

How Has This Been Tested?

Describe the tests you ran to verify your changes. Provide instructions for reproducing the testing process:

1. [Test case 1]
2. [Test case 2]

Checklist

• I have performed a self-review of my code
• I have added tests that prove my fix or feature works
• I have updated necessary documentation (e.g. frontpage README.md)
• Any dependent changes have been merged and published in downstream modules

Screenshots (if applicable)

If visual changes are made, include screenshots to demonstrate them.

Additional Notes

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[crypt0rr]

Thanks! ✌🏼