Added endpoint for fetching server-side variables.

pages/api/config.js

@@ -0,0 +1,14 @@
+import { ok, methodNotAllowed } from 'lib/response';
+
+export default async (req, res) => {
+  if (req.method === 'GET') {
+    return ok(res, {
+      basePath: process.env.BASE_PATH || '',
+      trackerScriptName: process.env.TRACKER_SCRIPT_NAME,
+      updatesDisabled: !!process.env.DISABLE_UPDATES,
+      telemetryDisabled: !!process.env.DISABLE_TELEMETRY,
+    });
+  }
+
+  return methodNotAllowed(res);
+};