Clarify the URL to be used for local Twilio usage with NGROK
Merge pull request #194 from daguar/clarify-local-twilio-setup-instructions

Clarify the URL to be used for local Twilio usage with NGROK
Add git clone instruction
Add tiny ToC to readme
Fix TOC links
Flush out 3rd party services, modularize deployment pieces, add screenshot for Twilio config
Add Heroku web=2 line and note on price because necessary for call-ins working at any time (dyno can\'t sleep)
Add note on secret token alternative