Update zh-cn to zh-hans, and update the icon when switch language Change-Id: I3e6d3e8aebec4584f863282082a11b36d7cee193
add development guide Change-Id: Id8fcac77eb5691e297f99cfe845c1b53bf1709bf
add test guide Change-Id: I3194ff9cd846ded71852fff0ad20e56c383bf77a