Add mdast-validate-links to dev-dependencies

Author: wooorm

.mdastrc

@@ -1,9 +1,11 @@
 {
   "output": true,
   "plugins": [
+    "comment-config",
     "lint",
     "github",
-    "comment-config"
+    "slug",
+    "validate-links"
   ],
   "settings": {
     "bullet": "*"

package.json

@@ -25,9 +25,11 @@
     "jscs": "^2.0.0",
     "jscs-jsdoc": "^1.0.0",
     "mdast": "^1.0.0",
+    "mdast-comment-config": "^1.0.0",
     "mdast-github": "^0.3.0",
     "mdast-lint": "^0.4.0",
-    "mdast-comment-config": "^1.0.0",
+    "mdast-slug": "^0.1.1",
+    "mdast-validate-links": "^0.3.1",
     "mocha": "^2.0.0"
   },
   "scripts": {