Clean up top-level directory

There are a lot of old files and folders of unclear functionality in the top-level directory. We should investigate what those do and move/rename/delete/replace/document them as they are confusing for people trying to get started with COOL.

• cool2tatl
• examples
• randcool
• benchmarks
• fact.conf
• install-remote.sh
• playground.hs
• randmu.py
• tatl-compatability-wrapper.sh
• version_gen.sh