feat: Adds custom css data for css-blocks at rules.

Reference: https://code.visualstudio.com/api/extension-guides/custom-data-extension

Author: Jackson Dean

packages/@css-blocks/vscode/css-blocks.css-data.json

@@ -0,0 +1,13 @@
+{
+  "version": 1.1,
+  "atDirectives": [
+    {
+      "name": "@block",
+      "description": "Import a block reference for use within another block"
+    },
+    {
+      "name": "@export",
+      "description": "Export a block reference to expose it to the template context of the current block"
+    }
+  ]
+}

packages/@css-blocks/vscode/package.json

@@ -1,35 +1,41 @@
 {
-	"private": true,
-	"name": "@css-blocks/vscode",
-	"description": "VSCode part of CSS Blocks' language server",
-	"author": "LinkedIn",
-	"license": "BSD-2-Clause",
-	"version": "0.0.1",
-	"repository": {
-		"type": "git",
-		"url": "https://github.com/LinkedIn/css-blocks"
-	},
-	"engines": {
-		"vscode": "^1.33.0"
-	},
-	"activationEvents": [
-	  "onLanguage:handlebars",
-	  "onLanguage:scss",
-	  "onLanguage:css"
-	],
-	"main": "./dist/extension",
-	"scripts": {
-		"update-vscode": "vscode-install",
-		"postinstall": "vscode-install",
-		"compile": "tsc --build",
-    "watch": "tsc --build --watch",
-    "test": "echo 'No tests.'"
-	},
-	"dependencies": {
-		"vscode-languageclient": "^5.2.1",
-		"@css-blocks/language-server": "^0.0.1"
-	},
-	"devDependencies": {
-		"vscode": "^1.1.35"
-	}
+  "private": true,
+  "name": "@css-blocks/vscode",
+  "description": "VSCode part of CSS Blocks' language server",
+  "author": "LinkedIn",
+  "license": "BSD-2-Clause",
+  "version": "0.0.1",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/LinkedIn/css-blocks"
+  },
+  "engines": {
+    "vscode": "^1.33.0"
+  },
+  "activationEvents": [
+    "onLanguage:handlebars",
+    "onLanguage:scss",
+    "onLanguage:css"
+  ],
+  "contributes": {
+    "css": {
+      "customData": [
+        "./css-blocks.css-data.json"
+      ]
+    }
+  },
+  "main": "./dist/extension",
+  "scripts": {
+    "update-vscode": "vscode-install",
+    "postinstall": "vscode-install",
+    "compile": "tsc --build",
+    "watch": "tsc --build --watch"
+  },
+  "dependencies": {
+    "vscode-languageclient": "^5.2.1",
+    "@css-blocks/language-server": "^0.0.1"
+  },
+  "devDependencies": {
+    "vscode": "^1.1.35"
+  }
 }