WP PLUGIN 申請指摘事項の修正

・$_POSTのサニタイズ
・echoのエスケープ
・readmeの修正

template/setting_post_custom_field.php

@@ -2,12 +2,12 @@
 	<?php if ( isset( $this->order_field ) && count( $this->order_field ) > 0 ): ?>
         <dl class="apop_setting_list_dd">
 			<?php foreach ( $this->order_field as $type => $items ): ?>
-                <dt><?php echo $this->labels[ $type ]; ?></dt>
+                <dt><?php echo esc_html($this->labels[ $type ]); ?></dt>
                 <dd>
                     <ul>
 						<?php foreach ( $items as $item ): ?>
 							<?php if ( ! empty( $item ) ): ?>
-                                <li><label><?php echo $item; ?></label>
+                                <li><label><?php echo esc_html($item); ?></label>
                                     <input type="text" name="<?php echo APOP_CUSTOM_FIELD_PREFIX . $item; ?>"
                                            value="<?php echo $this->get_custom_field_data( $item ); ?>"/>
                                 </li>