Update xonsh shell icons

[anki-code]

Please confirm this pull request meets the following requirements:

• I followed the contributing guidelines: https://github.com/github/explore/blob/main/CONTRIBUTING.md.
• This change is not self-promotion.

Which change are you proposing?

• Suggesting edits to an existing topic or collection
• Curating a new topic or collection
• Something that does not neatly fit into the binary options above

---

Editing an existing topic or collection

I'm suggesting these edits to an existing topic or collection:

• Image (and my file is *.png, square, dimensions 288x288, size <= 75 kB)
• Content (and my changes are in index.md)

Two changes:

1. xonsh topic image - it's just updating the icons to set the style like in https://github.com/xonsh/
2. xontrib topic image - it's refreshing the old image.

---

Please note: we will close your PR without comment if you do not check the boxes above and provide ALL requested information.

[Copilot]

Copilot wasn't able to review any files in this pull request.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[jmeridth]

@anki-code I saw you updated the readme on the project to the new icon but the website still shows the old icon. Is that getting updated later or the project will have different icons (one for README and one for website)? More out of curiousity. 😄

[anki-code]

Hey @jmeridth! You noticed correctly! We're updating the icon step by step: the GitHub repo, the Zulip community, the AppImage, the GitHub topic.
The website has a design concept with waves and a conch, so we're thinking about how we can integrate the new icon in the future.

From a top-level view, this is how we think about xonsh identity:

[anki-code]

Is that getting updated later or the project will have different icons (one for README and one for website)? More out of curiousity.

To satisfy your curiosity, we got out of the dilemma in this way (dev):

[Mahdi99mi]

bc1qr8e6kmev99jxnk7hpyhex434t59ke5tpvmnyd3