Add languages folder and add commented lines for a whitelist approach

WordPress.gitignore

@@ -7,6 +7,7 @@
 # you can delete this whole section/until Configuration.
 /wp-admin/
 /wp-content/index.php
+/wp-content/languages
 /wp-content/plugins/index.php
 /wp-content/themes/index.php
 /wp-includes/
@@ -33,3 +34,15 @@ wp-config.php
 
 # htaccess
 /.htaccess
+
+# All plugins
+#
+# Note: If you wish to whitelist plugins,
+# uncomment the next line
+#/wp-content/plugins
+
+# All themes
+#
+# Note: If you wish to whitelist themes,
+# uncomment the next line
+#/wp-content/themes