Add config/config.yaml to set default configurations. Use the config/local_config.yaml to set the custom configurations Change-Id: I22049e478b6440c765751c8f17663f36f33c277a
fix for docs link address Change-Id: I8539ba5a546621e543b2c4c83066489b98e308c5
Add English development documents Change-Id: I4b0e7dd346a6167df2a8a2f7380504cdbd32dc96