Make a MINGW package: mingw-w64-pdfium?

[Tao Zuhong]

**Is your feature request related to a problem? Please describe. **
Make a MINGW package, it will bring PDFium to more developers, thanks in advance.

Describe the solution you'd like
https://github.com/msys2/MINGW-packages/blob/master/mingw-w64-pdfium/PKGBUILD

[Paulo Coutinho]

Hi,

Im trying add support for Windows. When i reach it i will add the windows package for mingw.