Remove lib directory from version control

lib/plugins/external-script.js

@@ -1,28 +0,0 @@
-(function () {
-function handleExternalScript() {
-  var container = Docsify.dom.getNode('#main');
-  var scripts = Docsify.dom.findAll(container, 'script');
-
-  for (var i = scripts.length; i--;) {
-    var script = scripts[i];
-
-    if (script && script.src) {
-      var newScript = document.createElement('script');
-
-      Array.prototype.slice.call(script.attributes).forEach(function (attribute) {
-        newScript[attribute.name] = attribute.value;
-      });
-
-      script.parentNode.insertBefore(newScript, script);
-      script.parentNode.removeChild(script);
-    }
-  }
-}
-
-var install = function (hook) {
-  hook.doneEach(handleExternalScript);
-};
-
-window.$docsify.plugins = [].concat(install, window.$docsify.plugins);
-
-}());