Make build script more precise in its paths to watch

build.rs

@@ -47,10 +47,6 @@ impl TreeSitterParser {
 }
 
 fn main() {
-    // Only rerun if files in the vendor/ directory change.
-    // TODO: use specific source directories instead.
-    println!("cargo:rerun-if-changed=vendor");
-
     let parsers = vec![
         TreeSitterParser {
             name: "tree-sitter-bash".into(),
@@ -159,5 +155,11 @@ fn main() {
         },
     ];
 
+    // Only rerun if relevant files in the vendor/ directory change.
+    println!("cargo:rerun-if-changed=vendor/highlights");
+    for parser in &parsers {
+        println!("cargo:rerun-if-changed={}", parser.src_dir);
+    }
+
     parsers.par_iter().for_each(|p| p.build());
 }