Added svelte support

[niekdomi]

CLOSES #114

The tree-sitter query is from: https://github.com/tree-sitter-grammars/tree-sitter-svelte/tree/master/queries

note, that I'm not familiar with the tree-sitter grammar so the svelte.scm is vibe-coded... Seems to work though.

[Copilot]

Pull request overview

Adds initial Svelte language support to Codebook’s tree-sitter–based spell-checking pipeline, including query definitions, dictionary wiring, and integration tests.

Changes:

• Introduce LanguageType::Svelte and register it in LANGUAGE_SETTINGS with the tree-sitter-svelte-ng grammar.
• Add a Svelte tree-sitter query (svelte.scm) to extract spell-checkable regions (HTML text/attributes, plus <script>/<style> raw text).
• Add a Svelte dictionary source and integration tests covering HTML, script, and style sections.

Reviewed changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
README.md	Documents Svelte as partially supported.
crates/codebook/tests/test_svelte.rs	Adds integration tests validating Svelte spell-check extraction.
crates/codebook/src/queries/svelte.scm	Defines the tree-sitter query for Svelte spell-checkable nodes.
crates/codebook/src/queries.rs	Adds Svelte language type, language settings entry, and grammar mapping.
crates/codebook/src/dictionaries/repo.rs	Registers the svelte text dictionary repository source.
crates/codebook/Cargo.toml	Adds the tree-sitter-svelte-ng dependency for the codebook crate.
Cargo.toml	Pins tree-sitter-svelte-ng in workspace dependencies.
Cargo.lock	Locks the newly added dependency.