Add README for Vigenere, Solitaire

README.md

@@ -22,6 +22,8 @@ This is consistent with convention, but may not be expected.
 
 ## Code samples
 
+This is the last section of the readme. Nothing appears after this section.
+
 ### Caesar cipher
 
 Encrypt the text "Hello, World!" with a Caesar offset of 3 (that is, sending
@@ -51,6 +53,57 @@ encrypt_monoalphabetic("Hello, World!", "DEFGHIJKLMNOPQRSTUVWXYZABC")
 # outputs "KHOOR, ZRUOG!"
 ```
 
+Decrypt the same text, this time demonstrating the dictionary capability:
+
+```julia
+decrypt_monoalphabetic("Khoor, Zruog!", "DEFGHIJKLMNOPQRSTUVWXYZABC")
+# outputs "hello, world!"
+```
+
+Encrypt using a Dict:
+
+```julia
+encrypt_monoalphabetic("aBcbDd", Dict{Char, Char}('a' => '5', 'B' => '@', 'b' => 'o'))
+# outputs "5@coDd"
+```
+
+Notice that `encrypt_monoalphabetic` *does not* convert its input to uppercase
+when a Dict key is supplied.
+It simply makes all specified changes, and leaves the rest of the string unchanged.
+
+### Vigenère cipher
+
+Encrypt the text "Hello, World!" with a Vigenère cipher of key "ab":
+
+```julia
+encrypt_vigenere("Hello, World!", "ab")
+# outputs "HFLMOXOSLE"
+```
+
+Decrypt the same text with the offsets given as an array:
+
+```julia
+decrypt_vigenere("HFLMOXOSLE", [0, 1])
+# outputs "helloworld"
+```
+
+Notice that the offset `0` corresponds to the key `a`.
+
+### Solitaire cipher
+
+Encrypt the text "Hello, World!" with the Solitaire cipher, key "crypto":
+
+```julia
+encrypt_solitaire("Hello, World!", "crypto")
+# outputs "GRNNQISRYA"
+```
+
+Decrypt text with an initial deck specified:
+
+```julia
+decrypt_solitaire("EXKYI ZSGEH UNTIQ", collect(1:54))
+# outputs "aaaaaaaaaaaaaaa", as per https://www.schneier.com/code/sol-test.txt
+```
 
 [Caesar]: https://en.wikipedia.org/wiki/Caesar_cipher
 [Vigenère]: https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher