grammar: add new attributes

grammar.js

@@ -188,6 +188,7 @@ module.exports = grammar({
       prec(
         PREC.ATTRIBUTE_KEY,
         choice(
+          "direction",
           "shape",
           "label",
           "link",
@@ -244,11 +245,16 @@ module.exports = grammar({
         "stroke-width",
         "stroke-dash",
         "border-radius",
+        "double-border",
+        "font-size",
         "font-color",
         "shadow",
         "multiple",
         "animated",
-        "link"
+        "link",
+        "italic",
+        "bold",
+        "underline"
       ),
 
     _text_attr_key: ($) => "near",

src/grammar.json

@@ -769,6 +769,10 @@
       "content": {
         "type": "CHOICE",
         "members": [
+          {
+            "type": "STRING",
+            "value": "direction"
+          },
           {
             "type": "STRING",
             "value": "shape"
@@ -1006,6 +1010,14 @@
           "type": "STRING",
           "value": "border-radius"
         },
+        {
+          "type": "STRING",
+          "value": "double-border"
+        },
+        {
+          "type": "STRING",
+          "value": "font-size"
+        },
         {
           "type": "STRING",
           "value": "font-color"
@@ -1025,6 +1037,18 @@
         {
           "type": "STRING",
           "value": "link"
+        },
+        {
+          "type": "STRING",
+          "value": "italic"
+        },
+        {
+          "type": "STRING",
+          "value": "bold"
+        },
+        {
+          "type": "STRING",
+          "value": "underline"
         }
       ]
     },

src/node-types.json

@@ -376,6 +376,10 @@
     "type": "block_comment",
     "named": true
   },
+  {
+    "type": "bold",
+    "named": false
+  },
   {
     "type": "border-radius",
     "named": false
@@ -392,6 +396,10 @@
     "type": "dot",
     "named": true
   },
+  {
+    "type": "double-border",
+    "named": false
+  },
   {
     "type": "escape_sequence",
     "named": true
@@ -412,6 +420,10 @@
     "type": "font-color",
     "named": false
   },
+  {
+    "type": "font-size",
+    "named": false
+  },
   {
     "type": "height",
     "named": false
@@ -424,6 +436,10 @@
     "type": "integer",
     "named": true
   },
+  {
+    "type": "italic",
+    "named": false
+  },
   {
     "type": "label",
     "named": false
@@ -492,6 +508,10 @@
     "type": "true",
     "named": false
   },
+  {
+    "type": "underline",
+    "named": false
+  },
   {
     "type": "width",
     "named": false