6.2.1 metadata adjustments for nuget

update release notes v1.1.2

update release notes v1.1.1

netstandard compatibility (ArgumentNullException.ThrowIfNull)

extended: update release notes v1.0.2

Merge branch 'fix-issue-61-image-pointheight' into pdfsharp-extended

allow gitversion to recognize pdfsharp-extended branch as a release c…

…onfig