Add API documentation

Author: LorenzCK

docs/api-members-verify.md

@@ -0,0 +1,31 @@
+# Membership verification API
+
+Simple private API to check membership status based on e-mail.
+
+`POST https://dev.codemooc.net/api/members/verify?email=EMAILADDRESS`
+
+Requests _require_ a `Authorization` header with [Basic authentication information](https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication).
+
+Response format:
+
+```json
+{
+  "id": 123,
+  "primaryMail": "EMAILADDRESS",
+  "registeredOn": "2019-01-07T11:10:14",
+  "isMember": true,
+  "memberships": {
+    "2019": {
+      "issuedOn": "2019-01-11T14:50:52"
+    }
+  }
+}
+```
+
+| Attribute | Type | Description |
+| --- | --- | --- |
+| id | Numeric | Unique ID of the user (internal in CodeMOOC). |
+| primaryMail | String | Primary e-mail address, may not be equal to the input e-mail. |
+| registeredOn | UTC Date | Timestamp of registration on CodeMOOC. |
+| isMember | Boolean | Whether the user is currently a member. |
+| memberships | Object | Map of membership information by year. |