Update operation tips.

Signed-off-by: yushijinhun <yushijinhun@gmail.com>
Changed command-line usage.

Signed-off-by: yushijinhun <yushijinhun@gmail.com>
Fix some English syntax errors.
Set the window maximized when the window's size > 3/4 the screen's size.

Signed-off-by: yushijinhun <yushijinhun@gmail.com>
Merge branch 'pre-release-0.2' into develop