Usage notes:
1. open lyric panel with the button "Rep" on the mainwin

2. you have to download lyric file manully

3. when playing, select lyric panel, press "Insert" key on the keyboard,
and select lyric files, then it will load it to show

4. sometimes it will crash when meet other strange code in lyric,
you'd better change the code to utf8

5. default lyric path is audio_file/lrc/title.lrc

6. if it failed when copy lrc to default path, you can specify another one
in ~/.bmp/config: lyric_path=/path/to/lrc/