feat: use canonical Expressif icons

[Seddryck]

Summary

• add the canonical 64px, 128px, and 256px Expressif icons
• display the 256px icon in the repository and packaged README
• embed all icon sizes in the NuGet package and select the 128px asset as PackageIcon

Validation

• confirmed copied PNG SHA-256 hashes match the source assets in Seddryck/Expressif
• generated and inspected a package-only validation nupkg; all three images are present, PackageIcon resolves to the embedded 128px image, and README resolves to the embedded 256px image
• dotnet test Expressif.Syntax.sln --no-restore was attempted but stalled during the existing native grammar build without producing test results

close #56

[coderabbitai]

Important

Review available on request

• 🔍 Trigger review

Reviews should be triggered manually for repositories with fewer than 10 stars. Select Trigger review above or comment @coderabbitai review to review the latest changes. For a full review, comment @coderabbitai full review.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 69749144-22ad-473f-a902-e7cc2130abcb

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}