Migrate contents from monorepo

.gitignore

@@ -102,3 +102,6 @@ dist
 
 # TernJS port file
 .tern-port
+
+# Built assets
+lib/

README.md

@@ -0,0 +1,73 @@
+# @nteract/dropdown-menu
+
+This package contains a React component for rendering the drop-down element on a single cell. This drop-down provides users with the ability to hide and show cells, convert cells between different types, and more.
+
+## Installation
+
+```
+$ yarn add @nteract/dropdown-menu
+```
+
+```
+$ npm install --save @nteract/dropdown-menu
+```
+
+## Usage
+
+The example below showcases how we can use the components within this package to create a drop-down menu with actions specific to code cells.
+
+```javascript
+import {
+  DropdownMenu,
+  DropdownTrigger,
+  DropdownContent
+} from "@nteract/dropdown-menu";
+
+export default () => {
+  return (
+    <DropdownMenu>
+      <DropdownTrigger>
+        <button title="show additional actions">
+          <span className="octicon toggle-menu">
+            <ChevronDownOcticon />
+          </span>
+        </button>
+      </DropdownTrigger>
+      {type === "code" ? (
+        <DropdownContent>
+          <li
+            onClick={this.props.clearOutputs}
+            className="clearOutput"
+            role="option"
+            aria-selected="false"
+            tabIndex="0"
+          >
+            <a>Clear Cell Output</a>
+          </li>
+          <li
+            onClick={this.props.toggleCellInputVisibility}
+            className="inputVisibility"
+            role="option"
+            aria-selected="false"
+            tabIndex="0"
+          >
+            <a>Toggle Input Visibility</a>
+          </li>
+        </DropdownContent>
+      ) : null}
+    </DropdownMenu>
+  );
+};
+```
+
+## Documentation
+
+We're working on adding more documentation for this component. Stay tuned by watching this repository!
+
+## Support
+
+If you experience an issue while using this package or have a feature request, please file an issue on the [issue board](https://github.com/nteract/nteract/issues/new/choose) and add the `pkg:dropdown-menu` label.
+
+## License
+
+[BSD-3-Clause](https://choosealicense.com/licenses/bsd-3-clause/)