untrack the main.pdf and delete the prepare files
ignore the *.pdf files but track figures with pdf type
:boom:add the bib style file

thanks to the ZJU's template
add the test bib database
fix the appendix problem

it can be shown well after the backmatter, sounds grate!
test
设置了正文字体
解决冲突并合并
add math model and graphic model
修改
Merge remote-tracking branch 'lab/master' into develop