add core team section to readme
add core team section to readme

geoffp/patternlab-node,pattern-lab/patternlab-node,pattern-lab/patternlab-node,geoffp/patternlab-node,pattern-lab/patternlab-node,pattern-lab/patternengine-node-mustache,stevemartin/patternlab-node,heedfull/ClionaJoycePatterns,stevemartin/patternlab-node,heedfull/ClionaJoycePatterns,pattern-lab/patternlab-node