Add missing rust highlights

crates/zed/src/languages/rust/highlights.scm

@@ -1,6 +1,6 @@
 (type_identifier) @type
 (primitive_type) @type.builtin
-
+(self) @variable.builtin
 (field_identifier) @property
 
 (call_expression
@@ -15,6 +15,16 @@
 (function_item name: (identifier) @function.definition)
 (function_signature_item name: (identifier) @function.definition)
 
+(macro_invocation
+  macro: [
+    (identifier) @function.special
+    (scoped_identifier
+      name: (identifier) @function.special)
+  ])
+
+(macro_definition
+  name: (identifier) @function.special.definition)
+
 ; Identifier conventions
 
 ; Assume uppercase names are enum constructors
@@ -71,6 +81,7 @@
   "mod"
   "move"
   "pub"
+  "ref"
   "return"
   "static"
   "struct"
@@ -91,6 +102,13 @@
   (char_literal)
 ] @string
 
+[
+  (integer_literal)
+  (float_literal)
+] @number
+
+(boolean_literal) @constant
+
 [
   (line_comment)
   (block_comment)