initial workings for adding images to word outputs

[thebioengineer]

Summary

Thank you for contributing to gt! To make this process easier for everyone, please explain the context and purpose of your contribution. Also, list the changes made to the existing code or documentation.

Related GitHub Issues and PRs

• Ref: Word outputs including images #1272

Checklist

• I understand and agree to the Code of Conduct.
• I have listed any major changes in the NEWS.
• I have added testthat unit tests to tests/testthat for any new functionality.

TODO:

• make image insertion more generally work (right now markdown insertion is the only way)
• make the styling not corrupt (image inserts, but currently the doc needs to be "Repaired", destroying styling)

[CLAassistant]

All committers have signed the CLA.

[thebioengineer]

@rich-iannone - curious to get your feedback. also, I wanted to comment that fmt_image only has height as an option, not width. That works for html, since it will just scale the image, but word requires both height and width. the code as-is works with square images added, but it will square out any other images.

[rich-iannone]

@thebioengineer Sorry for the delay in responding here. I will try this out. About having just height as an option: we could also expose width but is possible to pre-calculate the latter given the height and having the image on disk? Unless inspecting an image requires extra packages for different graphics types, this might be worth exploring.

[thebioengineer]

We can definitely do that, but I'd need to sort out how to do that without Magick or other packages like that, since I was trying to not add a dependency

[rich-iannone]

LGTM!