Document Size landscape utility function

[bbrks]

Problem

I would like to produce a landscape sized PDF document but cannot easily do that

Proposed Solution

A built-in utility function to turn a portrait-dimension Size{} into lansdcape by flipping the X Y values

Alternatives Considered

Manually specifying Size{}, or a DIY helper function to rotate a Size to landscape

Scope

document (Layer 2: model)

[bbrks]

I have a branch for this but cannot open PRs against this repo without being a contributor - I acknowledge the contributing guide suggests discussing on issue first.

https://github.com/gpdf-dev/gpdf/compare/main...bbrks:gpdf:feat/size_landscape?expand=1