update site url in nikola conf

[oraNod]

Resolves #426

• Add a dev configuration file that sets the site url to the readthedocs location. This ensures that the production url does not leak into the dev site.
• Update readthedocs configuration to use the dev conf file.

[samccann]

Can't really review but it looks 'logically correct'. One question - should this be in draft until the go-live date so no one merges by mistake?

[oraNod]

Can't really review but it looks 'logically correct'. One question - should this be in draft until the go-live date so no one merges by mistake?

I don't think that's an issue. This is fine to merge now imo. The readthedocs domain will be used on our readthedocs dev/preview site like it is today. The ansible.com domain will get built in the container image, which is not currently deployed anywhere.

Another option here is to create a prod.conf.py that holds all the configuration values like site url that we want to deploy into the final production environment. We could then update the dockerfile to use that configuration but it feels unnecessary and would clutter the repo with configuration files.

I think it's better to put the "real deal" values in conf.py because it's the primary source of configuration. This is also why I thought it would be better to go with dev.conf.py instead of prod.conf.py. It's probably better to override with dev environment values.