Add dialout to the Daily phone example

[chadbailey59]

This PR renames the dialin-chatbot example to phone-chatbot, and adds dial-out support to the Daily example. We'd welcome another PR to add dial-out support for the Twilio example too. :)

[chadbailey59]

One thing of note: the on_dialout_answered hook doesn't seem to be firing.

[markbackman]

@chadbailey59 I pushed two commits:

1. I just found a typo in a variable (not yours)
2. I added more more explicit instructions in the README to keep developers on the rails when they test this. Please confirm that the steps and info are accurate. The Twilio example is unclear to me. I added the setup boilerplate to it, but we need clearer instructions about how to dial-in. As is, I would be left to guess on how to dial-in to a Twilio room. Ideally, the instructions are thorough enough that there is no ambiguity.