Added RSA key generator (fixes #16)

text/en/chapters/coding-encryption.md

@@ -503,11 +503,9 @@ A very popular public key system is RSA. For this section on public key systems,
 One thing you might like to do is to ask each student to generate their key pair, and then put their public key alongside their name in a shared spreadsheet (for example, a google doc). Then when the students would like to send an encrypted message to one of their classmates, they can look up the person's public key in the spreadsheet.
 {panel end}
 
-Firstly, you will need to generate a pair of keys using the key generator interactive. Note that each key consists of two numbers and the interactive separates them with a “+” (this does not mean addition). You should *keep the private key secret*, and *publicly announce the public key* so that your friends can send you messages (e.g. put it on the whiteboard, or email it to some friends). Make sure you save your keys somewhere so you don’t forget them – a text file would be best.
+Firstly, you will need to generate a pair of keys using the key generator interactive. You should *keep the private key secret*, and *publicly announce the public key* so that your friends can send you messages (e.g. put it on the whiteboard, or email it to some friends). Make sure you save your keys somewhere so you don’t forget them – a text file would be best.
 
-{comment}
-Put key generating interactive here
-{comment end}
+{interactive name="rsa-key-generator" type="in-page"}
 
 #### Encrypting messages with the public key