doc: replay: improve config description

First of all, this unordered list for `replay.refAction` introduces a term with a colon. This is exactly what a description list is, structurally. Let’s be stylistically consistent and use the desc. list markup construct. Let’s also drop the harmless but unneeded indentation. We can reuse the `::` delimiter since we use an open block. But for consistency use the typical nested description list delimiter, namely `;;`. Second, let’s replace the inline-verbatim `git replay` with a link to git-replay(1), since we are naming the command. But make that conditional so that we avoid a self-link inside git-replay(1).[1] † 1: See e.g. e7b3a768 (doc: git-init: rework config item init.templateDir, 2024-03-10) for another example of avoiding self-linking Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name> Signed-off-by: Junio C Hamano <gitster@pobox.com>