added config for optional copyright notice

tpl/main-footer.php

@@ -0,0 +1,25 @@
+<?php
+global $conf;
+
+if ($conf['license']) {
+    echo '<p>';
+    tpl_license($img = false, $imgonly = false, $return = false, $wrap = false);
+    echo '</p>';
+}
+
+if (tpl_getConf('copyright')) {
+    $copy = str_replace(
+        [
+            '%year%',
+            '%title%',
+            '%TITLE%',
+        ],
+        [
+            date('Y'),
+            $conf['title'],
+            dokuwiki\Utf8\PhpString::strtoupper($conf['title']),
+        ],
+        tpl_getConf('copyright')
+    );
+    echo '<p>' . $copy . '</p>';
+}