Add brakeman ignore

The site/ path is just for viewing components locally so I ignored the warning `Cross-Site Request Forgery` (code `17`, message: "`protect_from_forgery` should be called in `ApplicationController`")

Author: kengallego

.brakeman.ignore

@@ -0,0 +1,22 @@
+{
+  "ignored_warnings": [
+    {
+      "warning_type": "Cross-Site Request Forgery",
+      "warning_code": 17,
+      "fingerprint": "6f5239fb87c64764d0c209014deb5cf504c2c10ee424bd33590f0a4f22e01d8f",
+      "check_name": "ForgerySetting",
+      "message": "`protect_from_forgery` should be called in `ApplicationController`",
+      "file": "site/app/controllers/application_controller.rb",
+      "line": 3,
+      "link": "https://brakemanscanner.org/docs/warning_types/cross-site_request_forgery/",
+      "code": null,
+      "render_path": null,
+      "location": {
+        "type": "controller",
+        "controller": "ApplicationController"      },
+      "user_input": null,
+      "confidence": "High",
+      "note": "The `site/` path is meant for development and testing ONLY. It is never deployed to production and has no real users or sessions."
+    }
+  ]
+}