Documentation as how to setup a public controller

[erik78se]

juju-controller/README.md

Line 9 in 6b98013

## Usage

I've been trying to figure out what a best practice setup actually looks like with a controller. This might be the place to cover at least a basic example?

For example:

• If I deploy more than 3 units of this charm - will it enter into ha?
• What considerations do I need to make in terms of SSL/TLS?
• Example how to set the juju-mgmt-space in controller config, which will cause agents to communicate with controllers via that space.
• Example how to set the juju-ha-space in controller config that is the space used to replicate Mongo across the control plane.