Add `author` to prompt

[StefMa]

The default prompt looks like that:

summaraizer/cmd/summaraizer/summaraizer.go

Lines 225 to 233 in 9f0a066

	var defaultPromptTemplate = `
	I give you a discussion and you give me a summary.
	Each comment of the discussion is wrapped in a <comment> tag.
	Your summary should not be longer than 1200 chars.
	Here is the discussion:
	{{ range $comment := . }}
	<comment>{{ $comment.Body }}</comment>
	{{end}}
	`

Maybe we want to add the author to this somewhere as well?!
Maybe this gives the LLMs a bit more context about the discussion "who said what".

Maybe <comment author="AUTHOR">BODY</comment> 🤔