README: add some emacs note

Signed-off-by: Micky Ching <mickyching@163.com>
setting: re-format kill-region define

Signed-off-by: Micky Ching <mickyching@163.com>
linux: add ibus python setting and ibus-el-agent

Signed-off-by: Micky Ching <mickyching@163.com>