Adds straightforward example for feed operator

Response to:
The documentation on ==> should get to the point faster #2316

doc/Language/operators.pod6

@@ -2630,6 +2630,19 @@ operands are false, returns the last one.
 This X<feed> operator takes the result from the left and passes it to the
 next (right) routine as the last parameter.
 
+     my @array = (1, 2, 3, 4, 5);
+     @array ==> sum() ==> say();   # OUTPUT: «15␤»
+
+This simple example, above, is the equivalent of writing:
+
+     my @array = (1, 2, 3, 4, 5);
+     say(sum(@array));             # OUTPUT: «15␤»
+
+Or if using methods:
+
+     my @array = (1, 2, 3, 4, 5);
+     @array.sum.say;               # OUTPUT: «15␤»
+
 The precedence is very loose so you will need to use parentheses to
 assign the result or you can even just use another feed operator! In the
 case of routines/methods that take a single argument or where the first argument