Add neovim.io devcontainer feature

[Copilot]

Adds a new community devcontainer feature to install the nvim binary from neovim/neovim GitHub releases.

Changes

• src/neovim.io/devcontainer-feature.json — Feature metadata; supports version option (default: latest)
• src/neovim.io/install.sh — Downloads and installs nvim from GitHub releases; supports amd64 (x86_64) and arm64; exits with a clear error on unsupported architectures
• src/neovim.io/README.md — Standard auto-generated format docs
• test/neovim.io/test.sh — Verifies nvim --version output post-install

Usage

"features": {
    "ghcr.io/devcontainer-community/devcontainer-features/neovim.io:1": {}
}

To pin a version:

"features": {
    "ghcr.io/devcontainer-community/devcontainer-features/neovim.io:1": {
        "version": "0.10.3"
    }
}

Targets the nvim-linux-{arch}.tar.gz release assets introduced in v0.10.0; earlier versions are not supported.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add feature neovim.io</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add feature neovim.io #28

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[sebst]

@copilot New features need to be added to .github/workflows/test.yaml

[Copilot]

@copilot New features need to be added to .github/workflows/test.yaml

Added neovim.io to both the test-autogenerated and test-scenarios matrices in .github/workflows/test.yaml (commit 47ae521).