Add config.json.example to npm test

This commit extends the find command to also match the example config
file.

This should validate the syntax or this file to prevent syntax errors
for future pull request.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

package.json

@@ -6,7 +6,7 @@
   "license": "AGPL-3.0",
   "scripts": {
     "test": "npm run-script standard && npm run-script jsonlint",
-    "jsonlint": "find . -not -path './node_modules/*' -type f -name '*.json' | while read json; do echo $json ; jq . $json; done",
+    "jsonlint": "find . -not -path './node_modules/*' -type f -name '*.json' -o -type f -name '*.json.example' | while read json; do echo $json ; jq . $json; done",
     "standard": "node ./node_modules/standard/bin/cmd.js",
     "dev": "webpack --config webpack.config.js --progress --colors --watch",
     "build": "webpack --config webpack.production.js --progress --colors --bail",