Support for interactive forms

[freundTech]

Description

Interactive forms/AcroForm is a pdf feature that allows pdf files to include forms that can be filled out and saved using a supported pdf viewer. Pdf forms are notoriously hard to create with anything other than Adobe Acrobat, so having support for them in typst would be great.

Interactive forms are described in the pdf 1.7 standard section 12.7.

Supporting this feature would require:

• [ ] Implementing interactive form support in pdf-writer
• [ ] Designing functions and/or syntax for using interactive forms in typst
• [ ] Implementing interactive forms in typst

Use Case

Creating pdf forms that can be filled out.

[tingerrr]

I've started some initial work on this.