Icon request: icon-Briar
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I've just looked around the website and the issues section on the repository, and I couldn't find anything related to Briar.

## Icon

Here's the logo in PNG: [Briar](https://briarproject.org/img/briar_logo_large.png). I don't believe there's a need to keep the name on the bottom :)
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## Name Suggestion
Briar

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## Use Case
Same as for other IM apps such as Telegram and WhatsApp.
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