Adding feeds

How to add a new feed:

• Add new feed to config/feeds.yml
• Create private group on https://candy.freefeed.net
• Create private group on https://freefeed.net
• Update group description and avatar
• Create or reuse processor class
• Create or reuse normalizer class
• Test new feed processing on candy.
• Test on production.
• ⚠️ Open public access for the new group.

Testing new feed:

name = 'the-atlantic-photos'
feed = Service::FeedFinder.call(name)
loader = Service::LoaderResolver.call(feed)
content = loader.call(feed)
processor = Service::ProcessorResolver.call(feed)
normalizer = Service::NormalizerResolver.call(feed)
entities = processor.call(content)
entities.map { |e| normalizer.call(e[1]) }