Add crawlers for The Netherlands

[ojongerius]

Please follow https://github.com/volCommunity/vol-crawlers/blob/master/CONTRIBUTING.md#adding-new-countries--spiders

If you want an extra challenge, start work on #32 first and use the result to generate the Dutch spider/crawlers.

Note bene; This would be crawler of another language. A related issue in regards to multi language support is #38, but I'd consider that out of scope for this work. If you have any thoughts, feel free to chime in on that discussion!

Note that raising PRs if anything is unclear about the documentation is highly appreciated 😸

[ojongerius]

If you want to pair on this using video chat / screen sharing I'd be happy to help.

[ojongerius]

If you planned working on this, please hold off on it for now. Chatting to some people about potentially merging and the outcome of those talk influence the future of this code base.