feat: add nushell support

I love this tool! I added a small modification to support my favourite shell, [`nushell`](https://www.nushell.sh/), a new kind of shell where everything is structured data. After some polishing and adding tests, I thought it was time to contribute my changes back. Thank you so much for creating this great tool, @maaslalani! 🙏 I hope my contribution is up to your standards. Please let me know if I should change anything. ## Summary - Added nushell language support for syntax highlighting in slides - Added nushell support for .nu file extension mapping with `nu` command - Follows the same pattern as recent language additions (Haskell https://github.com/maaslalani/slides/pull/299, Scala https://github.com/maaslalani/slides/pull/298) <img width="2168" height="1238" alt="slides with nushell" src="https://github.com/user-attachments/assets/db6f0b6e-5848-4a41-a6b6-0c33d12db230" /> ## Code Structure ``` slides/ ├── internal/ │ ├── code/ │ │ ├── languages.go # Enhanced with nushell support │ │ ├── execute_test.go # Added nushell execution tests │ └── syntax/ # New module for syntax highlighting │ ├── nushell.go # Nushell highlighting logic │ └── nushell_test.go # Comprehensive test suite └── examples/ └── code_blocks.md # Enhanced nushell examples ``` ## 🎨 How Syntax Highlighting Works ### The Problem - Chroma (used by Glamour) doesn't natively support nushell syntax highlighting - Code blocks with `nu` identifiers showed as plain text ### The Solution 1. **Preprocessing**: Before markdown is rendered, replace ````nu` with ````bash` 2. **Fallback**: Bash syntax highlighting provides reasonable highlighting for most nushell syntax 3. **Future-Proof**: System ready for native nushell support when available in Chroma ### Code Flow ``` Markdown Input → Syntax Preprocessing → Glamour/Chroma → Highlighted Output ↓ ↓ ↓ ↓ ```nu → ```bash → Chroma → Highlighted echo "hi" echo "hi" Lexer Code Block ``` ``` ``` ## Testing - [x] Built and tested locally with `make test` - [x] Verified compilation with `make build` - [x] Test with actual nushell code blocks in markdown presentations - [x] Added nushell syntax highlighting ```shell make test go test ./... -short ? github.com/maaslalani/slides [no test files] ? github.com/maaslalani/slides/internal/cmd [no test files] ? github.com/maaslalani/slides/internal/model [no test files] ? github.com/maaslalani/slides/internal/server [no test files] ok github.com/maaslalani/slides/internal/code 0.752s ok github.com/maaslalani/slides/internal/file (cached) ok github.com/maaslalani/slides/internal/meta (cached) ok github.com/maaslalani/slides/internal/navigation (cached) ok github.com/maaslalani/slides/internal/process (cached) ok github.com/maaslalani/slides/internal/syntax 0.552s ok github.com/maaslalani/slides/styles (cached) ``` 🤖 Created with the help of `Claude Sonnet 4`