Fix highlights; Improve example

example.dust

@@ -1,12 +1,6 @@
-# Lists are created by grouping items in partheses and separating them with
-# commas.
+# Comment
+(1, 2, 3);
 
-numbers = (1, 2, 3);
-
-# To access the values in a list, use an integer as an index.
-
-x = numbers.0;
-y = numbers.1;
-z = numbers.2;
-
-assert_equal(x + y, z);
+random_integer();
+true;
+false;

highlights.scm

@@ -1,7 +1,20 @@
+(expression) @expression
+(value) @value
 (comment) @comment
 (operator) @operator
-(identifier) @identifier
+(identifier) @constant
 (value) @value
 (string) @string
-(tool) @function.builtin
+
+(integer) @number
 (float) @float
+
+(yield) @keyword
+(chain) @keyword
+
+(function) @function
+(tool) @function.builtin
+
+(empty) @null
+(boolean) @boolean
+(list) @list

src/grammar.json

@@ -1,5 +1,5 @@
 {
-  "name": "Dust",
+  "name": "dust",
   "rules": {
     "source_file": {
       "type": "REPEAT",

src/parser.c

@@ -1356,7 +1356,7 @@ extern "C" {
 #define extern __declspec(dllexport)
 #endif
 
-extern const TSLanguage *tree_sitter_Dust(void) {
+extern const TSLanguage *tree_sitter_dust(void) {
   static const TSLanguage language = {
     .version = LANGUAGE_VERSION,
     .symbol_count = SYMBOL_COUNT,