Added note about java_home to readme
Added note about java_home to readme

nathansgreen/idea-rust,ZJU-Shaonian-Biancheng-Tuan/idea-rust,AndrewTamm/idea-rust,tempbottle/idea-rust,ZJU-Shaonian-Biancheng-Tuan/idea-rust,tempbottle/idea-rust,nathansgreen/idea-rust,AndrewTamm/idea-rust,tempbottle/idea-rust,ZJU-Shaonian-Biancheng-Tuan/idea-rust,nathansgreen/idea-rust,AndrewTamm/idea-rust