Improve new syntax files and fix a region glitch

runtime/syntax/tex.yaml

@@ -4,23 +4,28 @@ detect:
     filename: "\\.tex$|bib|\\.bib$|cls|\\.cls$"
 
 rules:
+    # colorize the identifiers of {<identifier>} and [<identifier>]
     - identifier:
         start: "\\{"
         end: "\\}"
         rules: []
-
     - identifier:
         start: "\\["
         end: "\\]"
         rules: []
-
+    # numbers
     - constant.number: "\\b[0-9]+(\\.[0-9]+)?([[:space:]](pt|mm|cm|in|ex|em|bp|pc|dd|cc|nd|nc|sp))?\\b"
-    - symbol.brackets: "[{}\\[\\]]"
+    # let brackets have the default color again
+    - default: "[{}\\[\\]]"
     - special: "[&\\\\]"
-    - identifier.macro: "\\\\@?[a-zA-Z_]+"
-    - comment: "%.*"
+    # macros
+    - statement: "\\\\@?[a-zA-Z_]+"
+    # comments
+    - comment:
+        start: "%"
+        end: "$"
+        rules: []
     - comment:
         start: "\\\\begin\\{comment\\}"
         end: "\\\\end\\{comment\\}"
         rules: []
-