dev-api: add developer portal, OpenAPI spec, and Flatenbadet case study

- New /developers/ page with API docs, SDKs, pricing, use cases
- OpenAPI 3.0 spec for Orders, Missions, Photos, Analytics
- Case study: Glasskiosken i Flatenbadet — complete ROI analysis
- Updated /order/ with recurring missions and frequency dropdown

services/frilans-payout/node_modules/inherits/inherits.js

@@ -0,0 +1,9 @@
+try {
+  var util = require('util');
+  /* istanbul ignore next */
+  if (typeof util.inherits !== 'function') throw '';
+  module.exports = util.inherits;
+} catch (e) {
+  /* istanbul ignore next */
+  module.exports = require('./inherits_browser.js');
+}