Editor: add text columns to typography support.

Adds a text columns feature to the typography block support that uses CSS `column-count` for multi-column text.

Props ramonopoly, aaronrobertshaw.
Fixes #58549.

Built from https://develop.svn.wordpress.org/trunk@55985


git-svn-id: http://core.svn.wordpress.org/trunk@55497 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-theme-json.php

@@ -201,6 +201,7 @@ class WP_Theme_JSON {
 	 *              `--wp--style--root--padding-*`, and `box-shadow` properties,
 	 *              removed the `--wp--style--block-gap` property.
 	 * @since 6.2.0 Added `outline-*`, and `min-height` properties.
+	 * @since 6.3.0 Added `column-count` property.
 	 *
 	 * @var array
 	 */
@@ -228,6 +229,7 @@ class WP_Theme_JSON {
 		'border-left-width'                 => array( 'border', 'left', 'width' ),
 		'border-left-style'                 => array( 'border', 'left', 'style' ),
 		'color'                             => array( 'color', 'text' ),
+		'column-count'                      => array( 'typography', 'textColumns' ),
 		'font-family'                       => array( 'typography', 'fontFamily' ),
 		'font-size'                         => array( 'typography', 'fontSize' ),
 		'font-style'                        => array( 'typography', 'fontStyle' ),
@@ -334,6 +336,8 @@ class WP_Theme_JSON {
 	 * @since 6.1.0 Added `layout.definitions` and `useRootPaddingAwareAlignments`.
 	 * @since 6.2.0 Added `dimensions.minHeight`, 'shadow.presets', 'shadow.defaultPresets',
 	 *              `position.fixed` and `position.sticky`.
+	 * @since 6.3.0 Added support for `typography.textColumns`.
+	 *
 	 * @var array
 	 */
 	const VALID_SETTINGS = array(
@@ -395,6 +399,7 @@ class WP_Theme_JSON {
 			'fontWeight'     => null,
 			'letterSpacing'  => null,
 			'lineHeight'     => null,
+			'textColumns'    => null,
 			'textDecoration' => null,
 			'textTransform'  => null,
 		),
@@ -411,6 +416,7 @@ class WP_Theme_JSON {
 	 *              added new property `shadow`,
 	 *              updated `blockGap` to be allowed at any level.
 	 * @since 6.2.0 Added `outline`, and `minHeight` properties.
+	 * @since 6.3.0 Added support for `typography.textColumns`.
 	 *
 	 * @var array
 	 */
@@ -455,6 +461,7 @@ class WP_Theme_JSON {
 			'fontWeight'     => null,
 			'letterSpacing'  => null,
 			'lineHeight'     => null,
+			'textColumns'    => null,
 			'textDecoration' => null,
 			'textTransform'  => null,
 		),