Restore comment and language label highlighting

- Add back comment highlighting rules (template_comment, html_comment)
- Add embedded language name labels (json, alpine, js, css, etc.)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

queries/highlights.scm

@@ -1,5 +1,12 @@
 ; Waltzing Template Highlights
 
+; Comments (all template comment variants)
+(template_comment) @comment
+(template_comment_1) @comment
+(template_comment_2) @comment
+(template_comment_3) @comment
+(html_comment) @comment
+
 ; Keywords
 "@use" @keyword
 "@import" @keyword
@@ -90,5 +97,14 @@
 (escape_sequence) @escape
 (escape_at) @escape
 
+; Embedded language names
+"json" @label
+"alpine" @label
+"js" @label
+"javascript" @label
+"css" @label
+"style" @label
+"html" @label
+
 ; Variables (fallback)
 (identifier) @variable