add basic readme

Author: bmcmahen

Readme.md

@@ -1,9 +1,58 @@
 # react-image-enlarger
 
-A medium.com style image zoom component with gesture dismissal
+[![npm package](https://img.shields.io/npm/v/react-image-enlarger/latest.svg)](https://www.npmjs.com/package/react-image-enlarger)
+[![Follow on Twitter](https://img.shields.io/twitter/follow/benmcmahen.svg?style=social&logo=twitter)](https://twitter.com/intent/follow?screen_name=benmcmahen)
+
+A medium.com style image zoom component with gesture dismissal similar to that found in the iOS Photos app.
+
+## Features
+
+- Drag to dismiss
+- Optionally use a differernt enlarged image source
+- Optional loading indicator when loading the enlarged image
+- Spring based animations
 
 ## Install
 
+Install `react-image-enlarger` and `react-gesture-responder` using yarn or npm.
+
 ```
-yarn add react-image-enlarger
+yarn add react-image-enlarger react-gesture-responder
+```
+
+## Usage
+
+```jsx
+import Image from "react-image-enlarger";
+
+function SingleSource() {
+  const [zoomed, setZoomed] = React.useState(false);
+
+  return (
+    <Image
+      style={{ width: "200px", height: "auto" }}
+      zoomed={zoomed}
+      src="my-image.jpg"
+      alt="The best dog ever"
+      onClick={() => setZoomed(true)}
+      onRequestClose={() => setZoomed(false)}
+    />
+  );
+}
 ```
+
+## API
+
+Any additional props beyond the ones listed below are passed to the thumbnail image.
+
+| Name             | Type            | Default Value | Description                                                |
+| ---------------- | --------------- | ------------- | ---------------------------------------------------------- |
+| zoomed\*         | boolean         |               | Whether the enlarged image is shown                        |
+| onRequestClose\* | () => void;     |               | A callback for closing the zoomed image                    |
+| renderLoading    | React.ReactNode |               | Render a loading indicator                                 |
+| src\*            | String          |               | The thumbnail image source (and enlarged, if not provided) |
+| enlargedSrc      | String          |               | An optional larger image source                            |
+
+## License
+
+MIT

src/index.tsx

@@ -16,7 +16,7 @@ export interface ImageEnlargerProps extends React.HTMLAttributes<any> {
   onClick: () => void;
   enlargedSrc?: string;
   renderLoading?: React.ReactNode;
-  onRequestClose?: () => void;
+  onRequestClose: () => void;
   src: string;
 }