Add metadata to snippet code as comments

[sarahrichmond]

Add some basic metadata as comments in the snippets.

Example below:
From this KN resource: https://knowledgenet.co/dataset/ds-dga-755f2f61-b9fc-46e8-84d0-2e32ac448e8a. All metadata information should be readily available from KN (click on 'Get More Detail' on that page).

url = 'http://data.gov.au/storage/f/2013-05-12T210557/tmpgme16Yrecreational-fishing-spots.csv'
filename = 'tmpgme16Yrecreational-fishing-spots.csv'
urllib.request.urlretrieve(url, filename)

## Licence: Creative Commons Attribution 3.0 Australia
## Publisher: Department of Sustainability and Environment
## Contact Point: data.gov@finance.gov.au
## Full page: https://data.gov.au/dataset/755f2f61-b9fc-46e8-84d0-2e32ac448e8a```

[manhinli]

Depending on the resource, the requested metadata properties can be retrieved and should be easily added to snippets.