add comments

grammar.js

@@ -3,7 +3,7 @@ const spaces = repeat(" ");
 module.exports = grammar({
   name: "d2",
 
-  extras: ($) => [],
+  extras: ($) => [$.line_comment],
 
   word: ($) => $._word,
 
@@ -175,6 +175,8 @@ module.exports = grammar({
         seq("`", repeat(token.immediate(/[^`\n]+/)), "`")
       ),
 
+    line_comment: ($) => token(seq("#", /.*/)),
+
     _word: ($) => /[\w\d]+/,
 
     _emptyline: ($) => seq(spaces, $._eof),

queries/highlights.scm

@@ -3,12 +3,19 @@
 (identifier) @variable
 (attr_key) @keyword
 
+; Literals
 ;-------------------------------------------------------------------------------
 
 (string) @string
 (label) @string
 (attr_value) @string
 
+; Comments
+;-------------------------------------------------------------------------------
+
+(line_comment) @comment.line
+
+; Punctiation
 ;-------------------------------------------------------------------------------
 
 (arrow) @operator

src/grammar.json

@@ -969,6 +969,22 @@
         }
       ]
     },
+    "line_comment": {
+      "type": "TOKEN",
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "STRING",
+            "value": "#"
+          },
+          {
+            "type": "PATTERN",
+            "value": ".*"
+          }
+        ]
+      }
+    },
     "_word": {
       "type": "PATTERN",
       "value": "[\\w\\d]+"
@@ -1028,7 +1044,12 @@
       ]
     }
   },
-  "extras": [],
+  "extras": [
+    {
+      "type": "SYMBOL",
+      "name": "line_comment"
+    }
+  ],
   "conflicts": [
     [
       "identifier"

src/node-types.json

@@ -269,6 +269,10 @@
     "type": "label",
     "named": false
   },
+  {
+    "type": "line_comment",
+    "named": true
+  },
   {
     "type": "link",
     "named": false