Mention Set[G] as al algebra

Author: kryptt

algebraic-data-types/src/main/tut/index.html

@@ -206,6 +206,8 @@
 
 `List[G]` is the canonical implementation of the Monoid Algebra.
 
+`Set[G]` is the canonical implementation of Boolean Algebra.
+
 `List[Set[G]]` is the canonical implementation of Classical Linear Logic (CLL).
 
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