secret-handshake: Make examples in instructions.md clearer (#1896)

* Make examples in instructions.md clearer

For someone unfamiliar with binary, it's not immediately obvious that 19 can be viewed as 3+16. Directly presenting the solution for the exemplary input of 19 without this context might confuse the reader wondering how one arrives at the presented solution before it is explained in the following sentence.

* Update exercises/secret-handshake/description.md

Co-authored-by: Erik Schierboom <[email protected]>

Co-authored-by: Erik Schierboom <[email protected]>

Author: davidculley

exercises/secret-handshake/description.md

@@ -7,10 +7,10 @@ You and your fellow cohort of those in the "know" when it comes to
 binary decide to come up with a secret "handshake".
 
 ```text
-1 = wink
-10 = double blink
-100 = close your eyes
-1000 = jump
+00001 = wink
+00010 = double blink
+00100 = close your eyes
+01000 = jump
 
 
 10000 = Reverse the order of the operations in the secret handshake.
@@ -20,10 +20,8 @@ Given a decimal number, convert it to the appropriate sequence of events for a s
 
 Here's a couple of examples:
 
-Given the input 3, the function would return the array
-["wink", "double blink"] because 3 is 11 in binary.
+Given the decimal input 3, the function would return the array
+["wink", "double blink"] because the decimal number 3 is 2+1 in powers of two and thus `11` in binary.
 
-Given the input 19, the function would return the array
-["double blink", "wink"] because 19 is 10011 in binary.
-Notice that the addition of 16 (10000 in binary)
-has caused the array to be reversed.
+Let's now examine the input 19 which is 16+2+1 in powers of two and thus `10011` in binary.
+Recalling that the addition of 16 (`10000` in binary) reverses an array and that we already know what array is returned given input 3, the array returned for input 19 is ["double blink", "wink"].