Add additional signature information to doc json

[nojaf]

Subset of #1041

[zth]

Let's merge this and try it out as it's purely additive.

[nojaf]

Thank you for the review, @zth!

This leaves the PR in a bit of a puzzled state. What is the next action, and who should take it? There is both a remark and an approval.

My goal is to have a new version of the tool on npm if possible. What does it take to reach that level? As a contributor, I'm left to speculate about what comes next.

[zth]

Thank you for the review, @zth!

This leaves the PR in a bit of a puzzled state. What is the next action, and who should take it? There is both a remark and an approval.

My goal is to have a new version of the tool on npm if possible. What does it take to reach that level? As a contributor, I'm left to speculate about what comes next.

Well, I left a comment that I'd like to at least have acknowledged before we can merge.

[zth]

Great stuff! Releasing tonight.