Adding Category tag

[kamicut]

Picking up from #1, let's include a primary category tag in the metadata. Since this will be reflected on the website, the category is selected from this list (shared earlier via email):

• Population
• Natural Resources and Energy
• Employment and Household Economy
• Women
• Economic Sectors
• Banking and Finance
• Budget and Government Spending
• Housing
• Transport
• Trade
• Health Sector Performance
• Education
• Crime and Social Pathology
• Environment
• Communications

We can update the validator such that it fails if it's not one of these categories. This will make the website more focused. Caveat: since the website needs to know the category to render it in english and other languages, it has to be added by the contributor in a single language (or an identifier, like category-1, etc.). I can start by implementing it in English unless you have another suggestion.

Furthermore, if another category needs to exist, contributors can discuss it in this ticket.

cc @menayat

[kamicut]

I'm going to make a category map so that we can have multiple languages. Datasets will use a shortid for the category.

'Population -> 'population', 'Natural Resources and Energy' -> 'energy', 'Employment and Household Economy' -> 'employment', 'Women' -> 'women', 'Economic Sectors' -> 'economics', 'Banking and Finance' -> 'banking', 'Budget and Government Spending' -> 'budget', 'Housing' -> 'housing', 'Transport' -> 'transport', 'Trade' -> 'trade', 'Health Sector Performance' -> 'health', 'Education' -> 'education', 'Crime and Social Pathology' -> 'crime', 'Environment' -> 'environment', 'Communications' -> 'communications' 'Election and Regulations' -> 'elections'

cc @SoniaAmini @menayat