add language preference to config file

Author: Alejandra Trejo

config.yml

@@ -7,6 +7,16 @@ tags:
 template:
     name: security-on-github
     repo: security-template
+preferences:
+  - type: dropdown
+    name: language
+    label: Language
+    description: Choose your preferred language.
+    options:
+    - label: English
+      value: en
+    - label: 日本語
+      value: ja
 before:
   - type: updateBranchProtection
   - type: createPullRequest