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/pg-int8/README.md

@@ -0,0 +1,16 @@
+[![Build status][ci image]][ci]
+
+64-bit big-endian signed integer-to-string conversion designed for [pg][].
+
+```js
+const readInt8 = require('pg-int8');
+
+readInt8(Buffer.from([0, 1, 2, 3, 4, 5, 6, 7]))
+// '283686952306183'
+```
+
+
+  [pg]: https://github.com/brianc/node-postgres
+
+  [ci]: https://travis-ci.org/charmander/pg-int8
+  [ci image]: https://api.travis-ci.org/charmander/pg-int8.svg