Improve documentation

[bl4ck5un]

Need to add the following to https://town-crier.readthedocs.io/en/latest/

• How to use docker service to launch TC in one command
• supported data feed (some APIs have changed)
• How to play with Rinkeby

[yjiang0929]

Hi, I was experimenting with the Town Crier project recently and wonder if you have plans to add documentation on how to use the docker service along with the blockchain components. Thanks

[bl4ck5un]

Hi, You can find some insturctions on the use of TC docker images here: https://town-crier.readthedocs.io/en/latest/docker.html. In that setup we use infura to connect to the blockchain. If you're looking for instructions on running TC along with a local geth, we don't have one right now :P