new doc for adding fresh records at "new" placetype for country

[stepps00]

Add a new document, similar to the SF neighbourhoods doc, that outlines the steps needed to import new records at a given placetype into WOF. For example, WOF does not have admin2 records in Finland, but they've been added in a PR. Outline what it takes to add them, start to finish.

• find/verify data
• standardize props
• add source
• import/export in new PR
• PIP new features
• PIP descendants
• metafiles/sqlite/etc?