Update boolean.md, Removing space at the end of line

Author: x0rw

src/types/boolean.md

@@ -47,7 +47,7 @@ Like all primitives, the boolean type [implements][p-impl] the
 r[type.bool.expr]
 ## Operations on boolean values
 
-When using certain operator expressions with a boolean type for its operands, 
+When using certain operator expressions with a boolean type for its operands,
 they evaluate using the rules of [boolean logic].
 
 r[type.bool.expr.not]