Cleanup old stream stuff

/cc @wheresrhys @kaelig @laurent-muchacho @commuterjoy 

- Remove anything stream related from Grumman to avoid confusion!
- Rename article-card classes to article so it doesn't clash with cards
- Bring in template copying from dobi
This is a very generic name, very hard to grep. Sorry I don't have an alternative to suggest but that's something to think about.