doc: interpret-trailers: not just for commit messages

This command doesn’t interface with commits directly. You can
interpret or modify any kind of text, even though commit messages
are the most relevant.

The git(1) suite also isn’t restricted to only direct commit support
since git-tag(1) learned `--trailer` in 066cef7 (builtin/tag: add
--trailer option, 2024-05-05)

Now, we already introduce the command in the “Name” section as dealing
with commit messages as well. That is fine since that intro line needs
to remain pretty short.

Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: LemmingAvalanche

Documentation/git-interpret-trailers.adoc

@@ -15,8 +15,8 @@ git interpret-trailers [--in-place] [--trim-empty]
 DESCRIPTION
 -----------
 Add or parse trailers metadata at the end of the otherwise
-free-form part of a commit message. For example, in the following commit
-message
+free-form part of a commit message, or any other kind of text.
+For example, in the following commit message
 
 ------------------------------------------------
 subject