add some docs and changelog
diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst
index e5d8c65..0e3a451 100644
--- a/docs/hazmat/primitives/symmetric-encryption.rst
+++ b/docs/hazmat/primitives/symmetric-encryption.rst
@@ -275,6 +275,19 @@
Must be the same number of bytes as the ``block_size`` of the cipher.
Do not reuse an ``initialization_vector`` with a given ``key``.
+.. class:: CFB8(initialization_vector)
+
+ CFB (Cipher Feedback) is a mode of operation for block ciphers. It
+ transforms a block cipher into a stream cipher. The CFB8 variant uses an
+ 8-bit shift register.
+
+ **This mode does not require padding.**
+
+ :param bytes initialization_vector: Must be random bytes. They do not need
+ to be kept secret and they can be included in a transmitted message.
+ Must be the same number of bytes as the ``block_size`` of the cipher.
+ Do not reuse an ``initialization_vector`` with a given ``key``.
+
.. class:: GCM(initialization_vector, tag=None)
.. danger::