README.md in ralyxa-1.2.0 vs README.md in ralyxa-1.3.0

- old
+ new
@@ -134,13 +134,15 @@
   ask("What do you think of the Simple card I just sent?", card: simple_card)
 end
 
 # Standard card
 intent "SendStandardCard" do
-  standard_card = card("Hello World", "I'm alive!", "http://placehold.it/200")
+  standard_card = card("Hello World", "I'm alive!", "https://placehold.it/200")
   ask("What do you think of the Standard card I just sent?", card: standard_card)
 end
 ```
+
+> Card images must be under 2MB and available at an SSL-enabled (HTTPS) endpoint.
 
 ## Development
 
 After checking out the repo, run `bundle install` to install dependencies. Then, run `rspec` to run the tests. You can also run `irb` for an interactive prompt that will allow you to experiment.
 