docs: music bot example

[amishshah]

Please describe the changes this PR makes and why it should be merged:

This PR adds an example implementation of a music bot using discord.js. It focuses on:

• Reconnection logic
• Error handling and important state transitions
• Implementing a music queue
• Interesting uses of metadata in AudioResources

Status and versioning classification:

[codecov]

Codecov Report

Merging #107 (bb2854f) into main (0a92031) will not change coverage.
The diff coverage is n/a.

❗ Current head bb2854f differs from pull request most recent head 6d6365b. Consider uploading reports for the commit 6d6365b to get more accurate results

@@           Coverage Diff           @@
##             main     #107   +/-   ##
=======================================
  Coverage   63.46%   63.46%           
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  Files          18       18           
  Lines         813      813           
  Branches      191      191           
=======================================
  Hits          516      516           
  Misses        295      295           
  Partials        2        2           

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