feat(highlight): add TOML syntax highlighting

Use tree-sitter-toml-ng v0.7.0 from tree-sitter-grammars, which is
compatible with tree-sitter 0.26 (unlike the older tree-sitter-toml).

- Add tree-sitter-toml-ng dependency
- Add Toml variant to Language enum
- Add TOML_CONFIG with crate's HIGHLIGHTS_QUERY

Cargo.lock

@@ -1535,6 +1535,7 @@ dependencies = [
  "tree-sitter-nix",
  "tree-sitter-python",
  "tree-sitter-rust",
+ "tree-sitter-toml-ng",
  "tree-sitter-typescript",
  "tree-sitter-yaml",
  "walkdir",
@@ -1850,6 +1851,16 @@ dependencies = [
  "tree-sitter-language",
 ]
 
+[[package]]
+name = "tree-sitter-toml-ng"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e9adc2c898ae49730e857d75be403da3f92bb81d8e37a2f918a08dd10de5ebb1"
+dependencies = [
+ "cc",
+ "tree-sitter-language",
+]
+
 [[package]]
 name = "tree-sitter-typescript"
 version = "0.23.2"

Cargo.toml

@@ -39,6 +39,7 @@ toml     = "0.8"
 # Diagram rendering
 mermaid-rs-renderer = { version = "0.1", default-features = false }
 tree-sitter-md      = "0.5.2"
+tree-sitter-toml-ng = "0.7.0"
 
 # Patch dagre_rust to fix unwrap on None bug
 [patch.crates-io]

src/highlight.rs

@@ -91,6 +91,7 @@ pub enum Language {
     Nix,
     Python,
     Rust,
+    Toml,
     TypeScript,
     Yaml,
 }
@@ -110,6 +111,7 @@ impl Language {
             "nix" => Some(Language::Nix),
             "python" | "py" => Some(Language::Python),
             "rust" | "rs" => Some(Language::Rust),
+            "toml" => Some(Language::Toml),
             "typescript" | "ts" | "tsx" => Some(Language::TypeScript),
             "yaml" | "yml" => Some(Language::Yaml),
             _ => None,
@@ -231,6 +233,15 @@ static RUST_CONFIG: LazyLock<HighlightConfiguration> = LazyLock::new(|| {
     )
 });
 
+static TOML_CONFIG: LazyLock<HighlightConfiguration> = LazyLock::new(|| {
+    make_config(
+        tree_sitter_toml_ng::LANGUAGE.into(),
+        "toml",
+        tree_sitter_toml_ng::HIGHLIGHTS_QUERY,
+        "",
+    )
+});
+
 static TYPESCRIPT_CONFIG: LazyLock<HighlightConfiguration> = LazyLock::new(|| {
     make_config(
         tree_sitter_typescript::LANGUAGE_TYPESCRIPT.into(),
@@ -263,6 +274,7 @@ fn get_config(lang: Language) -> &'static HighlightConfiguration {
         Language::Nix => &NIX_CONFIG,
         Language::Python => &PYTHON_CONFIG,
         Language::Rust => &RUST_CONFIG,
+        Language::Toml => &TOML_CONFIG,
         Language::TypeScript => &TYPESCRIPT_CONFIG,
         Language::Yaml => &YAML_CONFIG,
     }