Rename as pageTemplates and support a nested config

lib/full-site-editing/page-templates.php

@@ -0,0 +1,35 @@
+<?php
+/**
+ * Support for page templates.
+ *
+ * @package gutenberg
+ */
+
+/**
+ * Load the page templates in Gutenberg.
+ *
+ * @param array $templates Theme page templates.
+ * @return array Modified templates.
+ */
+function gutenberg_load_fse_page_templates( $templates ) {
+	if ( ! gutenberg_is_fse_theme() ) {
+		return $templates;
+	}
+	$config_file = locate_template( 'experimental-theme.json' );
+	if ( ! file_exists( $config_file ) ) {
+		return $templates;
+	}
+	$data           = json_decode(
+		file_get_contents( $config_file ),
+		true
+	);
+	$page_templates = array();
+	if ( isset( $data['pageTemplates'] ) ) {
+		foreach ( $data['pageTemplates']  as $key => $page_emplate ) {
+			$page_templates[ $key ] = $page_emplate['title'];
+		}
+	}
+
+	return $page_templates;
+}
+add_filter( 'theme_page_templates', 'gutenberg_load_fse_page_templates' );

lib/load.php

@@ -79,7 +79,7 @@ function gutenberg_is_experiment_enabled( $name ) {
 require __DIR__ . '/full-site-editing.php';
 require __DIR__ . '/full-site-editing/default-template-types.php';
 require __DIR__ . '/full-site-editing/templates-utils.php';
-require __DIR__ . '/full-site-editing/custom-templates.php';
+require __DIR__ . '/full-site-editing/page-templates.php';
 require __DIR__ . '/templates-sync.php';
 require __DIR__ . '/templates.php';
 require __DIR__ . '/template-parts.php';