added jquery source map to chrome manifest

Chrome dev console is spitting out this error again:
```
Denying load of chrome-extension://ekmfaeljlmjncfnpfehgdhglekkblbga/scripts/vendor/jquery/jquery-2.0.3.min.map. Resources must be listed in the web_accessible_resources manifest key in order to be loaded by pages outside the extension. 
```

Adding the .map file to the manifest fixes the problem.