Update stateful.md

Author: oblomov-dev

docs/advanced/stateful.md

@@ -2,14 +2,14 @@
 
 By default, abap2UI5 runs stateless like any other UI5 freestyle app, meaning only REST calls are made to the ABAP backend.
 
-## Stateful Sessions
+#### Stateful Sessions
 
 In private and on-premise scenarios, abap2UI5 can also be used in stateful mode. Check out `Z2UI5_CL_DEMO_APP_135` and `Z2UI5_CL_DEMO_APP_137` for examples.
 
-## Locks
+#### Locks
 
 In certain scenarios, locking of business objects may be needed. Stateful sessions (described above) are one way to achieve this.
 
-## Infinite Transactions
+#### Infinite Transactions
 
-Another option is to create an infinite session in the backend that holds locks while the UI5 app still communicates statelessly. Check out the documentation [here](https://help.sap.com/docs/ABAP_PLATFORM_NEW/6568469cf5a1460a8d85c58b83d21ec2/47db6c68e4282972e10000000a42189b.html?locale=en-US) and see the issues [here](https://github.com/abap2UI5/abap2UI5/issues/2003) and [here](https://github.com/abap2UI5/abap2UI5/issues/1971) for more information.
+Another option is to create an infinite session in the backend that holds locks while the UI5 app still communicates statelessly. Check out the documentation [here](https://help.sap.com/docs/ABAP_PLATFORM_NEW/6568469cf5a1460a8d85c58b83d21ec2/47db6c68e4282972e10000000a42189b.html?locale=en-US) and see the issues [here](https://github.com/abap2UI5/abap2UI5/issues/2003) and [here](https://github.com/abap2UI5/abap2UI5/issues/1971) for more information.