Converter multple md-files into one pdf

[zqtprog]

Please add converter function for combining several or all md-files in folder into one PDF. Thanks :)

[yll690]

You can merge markdown first then print to pdf.

[PengWBiu]

您可以先合并 markdown，然后打印为 pdf。

beacuse the multi-markdown file is very big ,it will lead to markdown cant run or crash,so,i think need follow LaTex mode to combine multi-file mode to reduce the program crash issue