enh(doc): Add chapter about how to write a stream connector (#6189)

doc/en/_static/images/developer/lua/add_parameter.png

doc/en/_static/images/developer/lua/add_stream_connector.png

.../_static/images/developer/lua/archi_broker_lua_script.png

doc/en/_static/images/developer/lua/archi_broker_regular.png

doc/en/_static/images/developer/lua/archi_broker_stream.png

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doc/en/_static/images/developer/lua/describe_output.png

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doc/en/developer/index.rst

doc/en/developer/writestreamconnector.rst

doc/fr/_static/images/developper/lua/add_parameter.png

...fr/_static/images/developper/lua/add_stream_connector.png

..._static/images/developper/lua/archi_broker_lua_script.png

...fr/_static/images/developper/lua/archi_broker_regular.png

doc/fr/_static/images/developper/lua/archi_broker_stream.png

.../_static/images/developper/lua/broker_influxdb_output.png

doc/fr/_static/images/developper/lua/describe_output.png

.../_static/images/developper/lua/visualize_data_grafana.png

doc/fr/developper/index.rst

doc/fr/developper/writestreamconnector.rst