Is there a simple way to have default text pre-populate in the comment buffer when commiting code with magit?
If what you're looking for, is a default template message for a commit, you can put this in your
[commit] template = /path/to/a/.gitcommitmessagetemplate.txt
And inside .gitcommitmessagetemplate.txt, put whatever you want, example:
type scope: subject Body Breaking changes with description of the change, justification and migration notes. Closes|Refs #