add line number for jupyter

set_line_number_for_jupyter.js

/*If you want line numbers only for code cells, there is a simpler approach. Select a code cell, open the Chrome/Firefox JavaScript console, type the following lines:*/

```javascript
var cell = Jupyter.notebook.get_selected_cell();
var config = cell.config;
var patch = {
    CodeCell:{
        cm_config:{lineNumbers:true}
    }
}
config.update(patch)
```

/*
Then reload the page. These changes persist because Jupyter will create a json config file in .jupyter/nbconfig to store them. This method is from this page of the documentation, so read the docs for more config changes that you can make.*/