Merge pull request #1 from nteract/default

Default exports and README substance.

README.md

@@ -1,2 +1,18 @@
 # transformime-commonmark
+
 Transformer using commonmark.js
+
+```
+npm install transformime-commonmark
+```
+
+Usage with transformime:
+
+```
+> MarkdownTransformer = require('transformime-commonmark');
+> mdt = new MarkdownTransformer();
+
+> el = mdt.transform("```python\nimport this\n```\n", document);
+> el.innerHTML
+'<pre><code class="language-python">import this\n</code></pre>\n'
+```

src/commonmark-transformer.js

@@ -2,7 +2,7 @@
 
 var commonmark = require("commonmark");
 
-export class MarkdownTransformer {
+export default class MarkdownTransformer {
     constructor() {
         this.reader = new commonmark.Parser();
         this.writer = new commonmark.HtmlRenderer({