Add changeUserData to API docs

API.md

@@ -15,6 +15,7 @@
   - [/research/getResearch](#researchgetresearch)
   - [/research/performResearch](#researchperformresearch)
   - [/build/createBuilding](#buildcreatebuilding)
+  - [/auth/changeUserData](#authchangeuserdata)
 
 # 1. Description of custom types
 
@@ -233,6 +234,35 @@ updatedAt: Date
 }
 ```
 
+**OUTPUT:**
+```json
+{
+    "code": 200,
+    "message": "OK"
+}
+```
+
+## /auth/changeUserData
+
+**URL: PATCH** /auth/changeUserData/*:type*
+
+**DESCRIPTION:** Used to change user username, email or password. Type A access token required via Authorization header in addition to current password in body
+
+Type can be one of (anything other will throw ***400 Bad Request***):
+- username
+- email
+- password
+
+**BODY:**
+```json
+{
+    "password": "string",
+    "newUsername": "string",
+    "newEmail": "string",
+    "newPassword": "string"
+}
+```
+
 **OUTPUT:**
 ```json
 {