Add basic markdown support for assist chat messages

[krsilas]

Summary

This adds basic markdown formatting for messages in assist because LLMs often respond with markdown.
It does not support common markdown features like headlines, images and tables because they are currently not natively supported in SwiftUI

Screenshots

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Link to pull request in Documentation repository

Documentation: home-assistant/companion.home-assistant#

Any other notes

[bgoncal]

Looking great! Thanks for helping out with that.

One last request, can you also add a screenshot of how it looks in Apple Watch now? It worth testing if links are going to open in the in-app browser.

[bgoncal]

Same here

[home-assistant]

Please take a look at the requested changes, and use the Ready for review button when you are done, thanks 👍

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[bgoncal]

For the linter issue you can use bundle exec fastlane autocorrect

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 12 lines in your changes missing coverage. Please review.

Project coverage is 45.59%. Comparing base (4f60d68) to head (d7c6c3b).
Report is 65 commits behind head on master.

Files with missing lines	Patch %	Lines
Sources/Shared/Assist/AssistChatItem.swift	0.00%	12 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3689      +/-   ##
==========================================
+ Coverage   44.72%   45.59%   +0.87%     
==========================================
  Files         232      232              
  Lines       13911    14071     +160     
==========================================
+ Hits         6221     6416     +195     
+ Misses       7690     7655      -35     

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[bgoncal]

Out of curiosity, do you use Assist only by text? Markdown is not handled well by TTS (but that's not related to this PR goal of course)

[krsilas]

Out of curiosity, do you use Assist only by text? Markdown is not handled well by TTS (but that's not related to this PR goal of course)

@bgoncal Both. Depends on the situation and use case. Elevenlabs actually handles most cases just fine and uses simple markdown features for pronunciation. On voice only devices I have another assistant that has a special system prompt.

I would like to use text input more on mobile but theres also this issue: home-assistant/core#147975