Update hello_world.md

Author: oblomov-dev

docs/get_started/hello_world.md

@@ -62,7 +62,7 @@ CLASS z2ui5_cl_app_hello_world IMPLEMENTATION.
     client->view_display( z2ui5_cl_xml_view=>factory(
       )->page( |abap2UI5 - Hello World|
           )->text( |My Text|
-          )->button( text = 'post' press = client->_event( |POST| )
+          )->button( text = |post| press = client->_event( |POST| )
       )->stringify( ) ).
 
     CASE client->get( )-event.