ciphers: some style clean-up for consistency

Ciphers/CaesarCipher.php

@@ -2,6 +2,7 @@
 
 /**
  * Encrypt given text using caesar cipher.
+ *
  * @param string text text to be encrypted
  * @param int shift number of shifts to be applied
  * @return string new encrypted text

Ciphers/MorseCode.php

@@ -2,7 +2,9 @@
 
 /**
  * Encode text to Morse Code.
+ *
  * @param string text to encode
+ * @return string encoded text
  */
 function encode(string $text): string
 {

Ciphers/XORCipher.php

@@ -1,5 +1,7 @@
 <?php
-/* The XOR cipher is a type of additive cipher.
+
+/**
+ * The XOR cipher is a type of additive cipher.
  * Each character is bitwise XORed with the key.
  * We loop through the input string, XORing each
  * character with the key.
@@ -9,7 +11,6 @@
  * @param string $key The key to use.
  * @return string The encrypted string.
  */
- */
 function xorCipher(string $input_string, string $key)
 {