Added documentation for the user api

docs/api/users.md

 ## Users
+
+### GET `/user/name/:username`
+
+Request a users id based on his username. This will return 404 if the user does not exist in the
+service.
+
+#### Response body
+
+```typescript
+interface Body {
+    status: string;
+    user: {
+        id: string;
+        username: string;
+    };
+}
+```
+
+### GET `/user/:uuid/image`
+
+Get the image avatar for the user with the given uuid. If the user does not exist or the user has
+not set a avatar 404 will be returned. The returned image has the `Content-Type` set to `image/png`.
+
+### GET `/user/` [requires authentication]
+
+Get information on the user that is authenticated in the request.
+
+#### Response body
+
+```typescript
+interface Body {
+    status: string;
+    user: {
+        id: string;
+        username: string;
+        email: string;
+        realname: string;
+    };
+}
+```
+
+### GET `/user/tasks` [requires authentication]
+
+Get all the tasks that the authenticated user is assigned to and are not yet finished.
+
+#### Response body
+
+```typescript
+interface Body {
+    status: string;
+    tasks: {
+        id: string;
+        project: string;
+        name: string;
+        text: string;
+        icon: string;
+        priority: string;
+        status: string;
+        dependencies: string[];
+        requirements: {
+            role: string;
+            time: number;
+        }[];
+        assigned: {
+            user: string;
+            time: number;
+            finished: boolean;
+        }[];
+        created: number;
+        edited: number;
+        color: string;
+    }[];
+}
+```
+
+### GET `/user/work?since=X&to=X` [requires authentication]
+
+Get all the work items created by the authenticated user.
+
+#### Response body
+
+```typescript
+interface Body {
+    status: string;
+    work: {
+        id: string;
+        task: string;
+        user: string;
+        started: number;
+        finished: number;
+    }[];
+}
+```
+
+### GET `/user/activity?since=X&to=X` [requires authentication]
+
+Get the activity for the authenticated user.
+
+#### Response body
+
+```typescript
+interface Body {
+    status: string;
+    activity: {
+        day: string;
+        time: number;
+    }[];
+}
+```
+
+### GET `/user/completion?since=X&to=X` [requires authentication]
+
+Get the completion data for all tasks the user is assigned to.
+
+#### Response body
+
+```typescript
+interface Body {
+    status: string;
+    completion: {
+        open: number;
+        closed: number;
+        suspended: number;
+        overdue: number;
+    };
+}
+```
+
+### PUT `/user/` [requires authentication]
+
+Request an update to the authenticated users information.
+
+#### Request body
+
+```typescript
+interface Body {
+    realname?: string;
+    email?: string;
+}
+```
+
+### PUT `/user/image` [requires authentication]
+
+Update the image of the authenticated user. The image should be submitted as a file element in a
+FormData object called `image`.
+
+### GET `/user/:uuid` [requires authentication]
+
+Get information on the user with the given uuid.
+
+#### Response body
+
+```typescript
+interface Body {
+    status: string;
+    user: {
+        id: string;
+        username: string;
+        email: string;
+        realname: string;
+    };
+}
+```
+