Merged requested to merge remove-more-doc-mut into main
This refactors the
Document API until only the
.typeset() method requires
&mut self as a receiver.
In doing so, I also refactored the accumulation of warnings to be external to the Document struct.
You have read, and followed the guidance in, the CONTRIBUTING guide
The MR content has run through a pipeline, or at least has pipelines enabled.
There are no licence concerns with this contribution (The README clearly states Subplot is MIT-0)