Updating gitignore for Thumbs.db
Updating gitignore for Thumbs.db

Not specifying any directory means it'll catch all `Thumbs.db` files in any directory.
stevemartin/patternlab-node,geoffp/patternlab-node,geoffp/patternlab-node,pattern-lab/patternlab-node,heedfull/ClionaJoycePatterns,stevemartin/patternlab-node,pattern-lab/patternlab-node,pattern-lab/patternlab-node,pattern-lab/patternengine-node-mustache,heedfull/ClionaJoycePatterns,pattern-lab/patternlab-node