Updating project to net8, tidying up compile warnings for nullability…

… checks.

Merge pull request #17 from alfattack/page-break-inside

Re-perform layout on page break avoid

Merge pull request #16 from alfattack/page-break-inside

Page break inside improvement

Merge pull request #15 from alfattack/page-break-inside

Support page-break-inside: avoid

Merge pull request #14 from alfattack/html-decoding

Use HttpUtility.HtmlDecode for decoding html

Merge pull request #13 from alfattack/absolute-positioning

Support absolute positioning

Merge pull request #10 from alfattack/auto-size-images

Automatically determine image height if one isn't provided

Merge pull request #9 from albyoo/features/net60

Add image generator

Merge pull request #6 from albyoo/features/font-sizing

Update font size caluclation

Merge pull request #4 from albyoo/features/border-radius

Rename corner-radius to border-radius & Implement Skia border-radius.