Update README.md

Author: oblomov-dev

README.md

@@ -35,5 +35,8 @@ define table z2ui5_t_99 {
 * HTTP API: `/sap/bc/z2ui5standalone?sap-client=001&app_start=z2ui5_cl_my_standalone_app`
 * Credits: Created with the fantastic tool [abapmerge](https://github.com/larshp/abapmerge)
 
+#### Compatibility
+This repository works in both ABAO For Cloud and Standard ABAP. For old releases use the branch `702`.
+
 #### Issues
 For bug reports or feature requests, please open an issue in the [abap2UI5 repository.](https://github.com/abap2UI5/abap2UI5/issues)