Rephrased/changed some comments

Based on advice by @cosmoharrigan
Changed file name

In accordance with Scheme file name conventions
Removed file as file name changed
Merge pull request #744 from sebastianruder/relex2logic_readme

Relex2logic readme
Add sample of PLN rules using pattern matcher as unifier
Update README
Update README
Update README
Merge pull request #746 from cosmoharrigan/ruleengine

Add a sample of PLN rules for a rule engine using pattern matcher as unifier