feat(v2): Algolia search theme (#1440)

* feat(v2): Algolia search plugin

* patch PR #1440 (#1441)

* alternative implementation

* typo

* refactor noop

* rename SearchAlgolia -> SearchBar

* changes.md

packages/docusaurus-theme-search-algolia/src/index.js

@@ -0,0 +1,27 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+const path = require('path');
+
+const DEFAULT_OPTIONS = {};
+
+class DocusaurusThemeSearchAlgolia {
+  constructor(context, opts) {
+    this.options = {...DEFAULT_OPTIONS, ...opts};
+    this.context = context;
+  }
+
+  getName() {
+    return 'docusaurus-theme-search-algolia';
+  }
+
+  getThemePath() {
+    return path.resolve(__dirname, './theme');
+  }
+}
+
+module.exports = DocusaurusThemeSearchAlgolia;