doc: add ref to the 2 examples: client doing multi attribute retrieval, and poll operated (thread-less) service
doc: add ref to the 2 examples: client doing multi attribute retrieval, and poll operated (thread-less) service

ehamine/abus,ehamine/abus,relmachhour/abus,ehamine/abus,tectronics/abus,tectronics/abus,relmachhour/abus,tectronics/abus,relmachhour/abus