「📝」 doc(auth-api): logout doc added

doc/auth/logout.md

@@ -0,0 +1,24 @@
+# Logout
+
+Available endpoints:
+- GET `/logout`
+
+Common return:
+- 500 with response
+```json
+{
+    "error": "Internal server error"
+}
+```
+
+## GET `/logout`
+
+Used to logout the client (it just delete the cookie)
+
+Returns:
+- 200 with response and clear cookie
+```json
+{
+    "msg": "Logout successful"
+}
+```