docs: stable-kernel-rules: reduce redundancy

Explain the general concept once in the intro to keep things somewhat
shorter in the individual points.
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/106e21789e2bf02d174e1715b49cd4d30886d51f.1714367921.git.linux@leemhuis.info

Documentation/process/stable-kernel-rules.rst

@@ -79,10 +79,9 @@ stable tree without anything else needing to be done by the author or
 subsystem maintainer.
 
 To sent additional instructions to the stable team, use a shell-style inline
-comment:
+comment to pass arbitrary or predefined notes:
 
- * To specify any additional patch prerequisites for cherry picking use the
-   following format in the sign-off area:
+ * Specify any additional patch prerequisites for cherry picking:
 
    .. code-block:: none
 
@@ -114,8 +113,7 @@ comment:
    prerequisite of patch2 if you have already marked patch1 for stable
    inclusion.
 
- * For patches that may have kernel version prerequisites specify them using
-   the following format in the sign-off area:
+ * Point out kernel version prerequisites:
 
    .. code-block:: none
 
@@ -132,14 +130,13 @@ comment:
    Note, such tagging is unnecessary if the stable team can derive the
    appropriate versions from Fixes: tags.
 
- * To delay pick up of patches, use the following format:
+ * Delay pick up of patches:
 
    .. code-block:: none
 
      Cc: <stable@vger.kernel.org> # after 4 weeks in mainline
 
- * For any other requests, just add a note to the stable tag. This for example
-   can be used to point out known problems:
+ * Point out known problems:
 
    .. code-block:: none