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/fast-safe-stringify/CHANGELOG.md

@@ -0,0 +1,17 @@
+# Changelog
+
+## v.2.0.0
+
+Features
+
+- Added stable-stringify (see documentation)
+- Support replacer
+- Support spacer
+- toJSON support without forceDecirc property
+- Improved performance
+
+Breaking changes
+
+- Manipulating the input value in a `toJSON` function is not possible anymore in
+  all cases (see documentation)
+- Dropped support for e.g. IE8 and Node.js < 4