Create gist for each code block

I will modify the plugin so it creates a gist for each code block in markdown. I also want to anotate the language of the gist so I can do something like this:

``` scala
def someScalaFunction(x: Int) = x + 1
```

it should create a gist with _.scala_ extension so the code gets render with the Scala colors. 

I also might one to insert the gist url below the code block. :)
