Fixed description and tags in NuSpec.
Fixed description and tags in NuSpec.

pvginkel/PdfiumViewer,ballance/PdfiumViewer,pasysxa/PdfiumViewer,stevewangamm/PdfiumViewer,pasysxa/PdfiumViewer,pvginkel/PdfiumViewer,modulexcite/PdfiumViewer,MichalGrzegorzak/PdfiumViewer,ballance/PdfiumViewer,stevewangamm/PdfiumViewer,modulexcite/PdfiumViewer,MichalGrzegorzak/PdfiumViewer