Add exit sequences to triggers

Use t.exit { <what to do when exiting> } inside the trigger body to tell the
trigger to do something before the program exits.
Add saving/loading the chain, and folder for books

The books are for the bot to learn. They will be .gitignore'd, however.
Add .gitignore to ignore the readfrombooks.rb file
Include chains.json in the gitignore

now to remove it from the directory....
untracked file