[PATCH v4 2/2] doc: format-rev: use [synopsis] on code block

From: Kristoffer Haugsbakk <redacted>

This code block uses the placeholder `<subject>`. Let’s highlight this
placeholder properly by using the `synopsis` open block definition which
was introduced in a34d1d53 (doc: convert git-show to synopsis style,
2026-02-06). This renders the block like a code block but with emphasis
styling on placeholders, just like inline-verbatim (`) in running text.

Yes, note that open blocks since commit a34d1d53 can, on synopsis-style
docs like this one, be immediately preceded by `[synopsis]`, just like
the command synopsis is:

    [synopsis]
    (EXPERIMENTAL!) git format-rev - [...]

Cf. verse-style:

    [verse]
    'git name-rev' [...]

Signed-off-by: Kristoffer Haugsbakk <redacted>
---

Notes (series):
    v4:
    • Fix block: use open block, not code block.[1] This is what was
      done for the synopsis blocks in commit a34d1d53, the commit
      mentioned here. I have tested this with what I believe are the
      use-asciidoc (tool) and use-asciidoctor (tool):
    
          make doc
          make USE_ASCIIDOCTOR=1 doc
    
      And they didn’t give any warnings. And they produced the correct
      result.
    
      🔗 1: https://lore.kernel.org/git/xmqqfr0hqzvl.fsf@gitster.g/ (local)
    • Msg: Rewrite or flesh out the message to reflect this newfound
      knowledge
    • Remove Ack from the previous round since I had to make these
      changes
    ---
    v3: add Ack: https://lore.kernel.org/git/an2Wwe4ytilGoyHz@pks.im/ (local)
    v2:
    • Add a paragraph to contrast synopsis code blocks with synopsis
      command description after talk with Patrick on v1[1]
    
      🔗 1: https://lore.kernel.org/git/ansWZxZ6lB0tYIJD@pks.im/ (local)

 Documentation/git-format-rev.adoc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/git-format-rev.adoc b/Documentation/git-format-rev.adoc
index 19241837345..c2268c92b56 100644
--- a/Documentation/git-format-rev.adoc
+++ b/Documentation/git-format-rev.adoc

@@ -96,9 +96,10 @@ The mode `--stdin-mode=text` replaces each object name with the
 formatted commit, i.e. the format `"%s"` would transform some commit
 object name to `"<subject>"` without any termination. Like this:
 
-----
+[synopsis]
+--
 Did we not fix this in "<subject>"?
-----
+--
 
 It is safe to interactively read and write from this command since each
 record is immediately flushed.

-- 
2.55.0.13.g85d2d65e389