config: use --value instead of value-pattern

This option was introduced in a series of commits from fe3ccc7 (Merge
branch 'ps/config-subcommands', 2024-05-15) and deprecated
`value-pattern`.  But `value-pattern` is still used throughout the doc.

The deprecated modes have been quarantined in the “Deprecated Modes”
section.  So let’s only use `--value=<pattern>` in the rest of the doc.

Acked-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: LemmingAvalanche

Documentation/git-config.adoc

@@ -26,7 +26,7 @@ escaped.
 
 Multiple lines can be added to an option by using the `--append` option.
 If you want to update or unset an option which can occur on multiple
-lines, a `value-pattern` (which is an extended regular expression,
+lines, `--value=<pattern>` (which is an extended regular expression,
 unless the `--fixed-value` option is given) needs to be given.  Only the
 existing values that match the pattern are updated or unset.  If
 you want to handle the lines that do *not* match the pattern, just
@@ -109,7 +109,7 @@ OPTIONS
 
 --replace-all::
 	Default behavior is to replace at most one line. This replaces
-	all lines matching the key (and optionally the `value-pattern`).
+	all lines matching the key (and optionally `--value=<pattern>`).
 
 --append::
 	Adds a new line to the option without altering any existing
@@ -209,10 +209,10 @@ See also <<FILES>>.
 Use `--no-value` to unset _<pattern>_.
 
 --fixed-value::
-	When used with the `value-pattern` argument, treat `value-pattern` as
+	When used with `--value=<pattern>`, treat _<pattern>_ as
 	an exact string instead of a regular expression. This will restrict
 	the name/value pairs that are matched to only those where the value
-	is exactly equal to the `value-pattern`.
+	is exactly equal to _<pattern>_.
 
 --type <type>::
   'git config' will ensure that any input or output is valid under the given