add code readme.md code example

Example 1: readme.md code snippet

I think you should use an
`<addr>` element here instead.

Example 2: markdown code snippet

```javascript
var s = "JavaScript syntax highlighting";
alert(s);
```
 
```python
s = "Python syntax highlighting"
print s
```
 
```
No language indicated, so no syntax highlighting. 
But let's throw in a <b>tag</b>.
```