Fix indentation in readme

Author: anakinj

README.md

@@ -216,26 +216,26 @@ puts decoded_token
 An object implementing custom signing or verification behaviour can be passed in the `algorithm` option when encoding and decoding. The given object needs to implement the method `valid_alg?` and `verify` and/or `alg` and `sign`, depending if object is used for encoding or decoding.
 
 ```ruby
-  module CustomHS512Algorithm
-    def self.alg
-      'HS512'
-    end
+module CustomHS512Algorithm
+  def self.alg
+    'HS512'
+  end
 
-    def self.valid_alg?(alg_to_validate)
-      alg_to_validate == alg
-    end
+  def self.valid_alg?(alg_to_validate)
+    alg_to_validate == alg
+  end
 
-    def self.sign(data:, signing_key:)
-      OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha512'), data, signing_key)
-    end
+  def self.sign(data:, signing_key:)
+    OpenSSL::HMAC.digest(OpenSSL::Digest.new('sha512'), data, signing_key)
+  end
 
-    def self.verify(data:, signature:, verification_key:)
-      ::OpenSSL.secure_compare(sign(data: data, signing_key: verification_key), signature)
-    end
+  def self.verify(data:, signature:, verification_key:)
+    ::OpenSSL.secure_compare(sign(data: data, signing_key: verification_key), signature)
   end
+end
 
-  token = ::JWT.encode({'pay' => 'load'}, 'secret', CustomHS512Algorithm)
-  payload, header = ::JWT.decode(token, 'secret', true, algorithm: CustomHS512Algorithm)
+token = ::JWT.encode({'pay' => 'load'}, 'secret', CustomHS512Algorithm)
+payload, header = ::JWT.decode(token, 'secret', true, algorithm: CustomHS512Algorithm)
 ```
 
 ## Support for reserved claim names