Update API Generator to take versions as input

WordPress API is currently only reporting an `offer` of 5.7.1 as the latest version so alternative route is needed for back-ported versions

api-hashes-generator.php

@@ -6,16 +6,24 @@
 */
 
 $version_url = 'https://api.wordpress.org/core/version-check/1.7/';
-$checksum_url = 'https://api.wordpress.org/core/checksums/1.0/?version=';
-$locale = '&locale=en_US';
 
 $versions = file_get_contents( $version_url );
 $versions = json_decode( $versions );
 
 foreach( $versions->offers as $wp_version ) {
-	$filename = dirname( __FILE__ ) . '/' . 'hashes-' . $wp_version->version . '.php';
+	create_hashes( $wp_version->version );
+}
+
+if ( isset( $_GET['version'] ) ) {
+	create_hashes( $_GET['version'] );
+}
+
+function create_hashes( $wp_version ) {
+	$checksum_url = 'https://api.wordpress.org/core/checksums/1.0/?version=';
+	$locale = '&locale=en_US';
+	$filename = dirname( __FILE__ ) . '/' . 'hashes-' . $wp_version . '.php';
 	if ( ! file_exists( $filename ) ) {
-		$checksums = file_get_contents( $checksum_url . $wp_version->version . $locale );
+		$checksums = file_get_contents( $checksum_url . $wp_version . $locale );
 		$checksums = json_decode( $checksums, true );
 		$hashes = "<?php\n" . '$filehashes = array(' . "\n";
 		foreach ( $checksums['checksums'] as $file => $checksum ) {
@@ -25,6 +33,6 @@
 		}
 		$hashes .= ");\n";
 		file_put_contents( $filename, $hashes );
-		echo 'Hash file created for ' . $wp_version->version . "\n";
+		echo 'Hash file created for ' . $wp_version . "\n";
 	}
 }